Congressional Requesters 

United States Government Accountability Office

GAO

October 2004 AMERICAN 

COMMUNITY 

SURVEY 

Key Unresolved Issues

GAO-05-82 
www.gao.gov/cgi-bin/getrpt?GAO-05-82.

To view the full product, including the scope 

and methodology, click on the link above. 

For more information, contact Robert P. 

Parker (202) 512-9750 or parkerr@gao.gov. 

Highlights of GAO-05-82, a report to 

congressional requesters 

October 2004

AMERICAN COMMUNITY SURVEY

Key Unresolved Issues 

The Census Bureau’s development of the American Community Survey goes 

back several decades and has included intensive research and field testing 

programs, as well as substantial outreach efforts, in particular through the 

reports and workshops at the National Academy of Sciences (NAS). 

However, if the ACS is to be an adequate replacement for the Decennial 

Census long form as the major source of data on small geographic areas and 

if it is to provide similar annual data for larger areas, the Census Bureau will 

need to 

• incorporate in a timely manner the resolution of issues it has already 

identified in the ACS testing and 2000 Decennial Census evaluation 

programs, such as the residence concept, group quarters, and questions 

on disability; 

• complete the ACS testing plan as originally planned, such as the 

comparison and evaluation of long form–ACS supplementary survey data 

at the state level, to identify other unresolved issues and to provide 

information for users of 2000 Decennial Census long-form data that will 

be necessary for the transition to the full ACS; 

• evaluate and consult with stakeholders and users on the resolution of 

issues identified in this report, such as the methodology for deriving 

population and housing controls, guidance for users on the impact of the 

characteristics of multiyear averages for small geographic areas, and the 

presentation of dollar-denominated values; 

• coordinate the results of the testing program for the 2010 Decennial 

Census short form with the ACS implementation schedule; and 

• resolve all issues so that the ACS estimates beginning with 2008 are 

consistent with the ACS estimates for 2009–12 and with the 2010 Census 

short form. 

Although the Census Bureau has solicited advice from external stakeholders 

and users and has supported research by its own staff on most of the issues 

identified in this report, there is no indication that the Census Bureau has yet 

followed this advice or implemented plans for consultation on resolving 

these issues. In addition, it has been more than a year since the Census 

Bureau announced that it was looking into establishing an ACS partnership 

program that would involve advisory groups and expert panels to improve 

the program, but no such program has been established. 

Another issue related to the proposed ACS is how the Census Bureau might 

provide more timely and reliable small geographic area data. This goal could 

be accomplished, but it would require additional funding. The most direct 

approach would be to increase the sample size for 2009–11. This increase 

would enable the Bureau to provide small geographic area data that would 

be the replacement for the 2010 Census long form 1 year earlier. 

The Congress asked GAO to review 

operational and programmatic 

aspects of the Census Bureau’s ACS 

that will affect the reliability of 

small geographic area data. The 

ACS will be a mail survey of about 

3 million households annually, 

whose results will be cumulated 

over 5 years to produce estimates 

that will replace information 

previously provided by the 

Decennial Census long form. In 

addition, annual data will be 

published for geographic areas with 

65,000+ populations and as 3-year 

averages for areas with populations 

of 20,000 to 65,000. Annual data will 

be published beginning in 2006 with 

data for 2005. The 5-year averages 

for 2008–12 will provide data for 

small geographic areas. 

The Secretary of Commerce should 

direct the Census Bureau to revise 

the ACS evaluation and testing 

plan, focusing on issues GAO 

identifies; give stakeholders 

meaningful input on related 

decisions; and make the underlying 

information public. The Secretary 

should direct the Bureau to set a 

schedule for incorporating 

operational and programmatic 

changes into the 5-year averages 

for 2008–12. 

In commenting on a draft of this 

report, the Secretary stated that 

Commerce has already addressed 

most of the key issues we identified 

in this report. We believe, however, 

that the matters are not being fully 

addressed and need further 

attention by Commerce. 
Page i GAO-05-82 American Community Survey 

Letter 1

Results in Brief 3 

Background 6 

Outstanding Issues Jeopardize ACS’s Replacement of the Long 

Form 10 

Improving Timeliness and Quality of Small Geographic Area Data 

Would Increase Costs 21 

Resolving Outstanding Issues Needs a Time Schedule 22 

Conclusions 25 

Recommendations for Executive Action 26 

Agency Comments and Our Evaluation 26 

Appendix I Scope and Methodology 33 

Appendix II Recent NAS Findings on Continuous Measurement 

and the ACS 35 

1998 NAS Workshop on the ACS 36 

2000 Interim Report 39 

2001 Letter Report 41 

2003 Interim Report 42 

The 2000 Census: Counting under Adversity 45 

Appendix III The Decennial Census Long Form and the Evolution 

of the ACS Plan 47 

Decennial Census Long Form 47 

Evolution of ACS Plan 47 

Appendix IV Continuous Measurement ACS Testing and 

Development Program 52 

Appendix V Current Status of Unresolved Issues 62 

Independent Controls for Population and Housing Characteristics 62 

Operational Issues 70 

Valuation and Presentation of Dollar-Denominated Data Items 73 

Evaluations of ACS, Long-Form, and CPS Data Comparisons 76 

Information on Key Properties of Multiyear Averages 81 

Contents 
Page ii GAO-05-82 American Community Survey 

External Consultation 86 

Appendix VI Comments from the Department of Commerce 89 

Appendix VII GAO Contacts and Staff Acknowledgments 104 

GAO Contacts 104 

Staff Acknowledgments 104 

Bibliography 105 

History of the Long Form and Mid-Decade Census 105 

Census Bureau ACS Reports 105 

Census Bureau Advisory Committee Presentations 107 

Census Bureau Continuous Measurement Series 108 

Census Bureau Internal Reports 108 

Census 2000 Evaluation Reports 109 

Census Bureau 2003 JSM Staff Papers 109 

Other Census Bureau Staff Research Papers 110 

Association of Public Data Users Papers 111 

Congressional Hearings and Testimony 112 

Other Reports and Papers 112 

Related GAO Products 114 

Tables 

Table 1: ACS Milestone Events and Unresolved Issues, 2004–13 23 

Table 2: Continuous Measurement and ACS Funding, Fiscal Years 

1995–2005 49 

Table 3: The 2000 Census Long Form and ACS Use of Independent 

Controls for Population and Housing Characteristics 63 

Table 4: Population Comparison for Counties in 2000 from ICPE 

and 2000 Census by County Size 67 
Page iii GAO-05-82 American Community Survey 

Abbreviations

ACS American Community Survey 

ASA American Statistical Association 

BEA Bureau of Economic Analysis 

BLS Bureau of Labor Statistics 

C2SS Census 2000 Supplementary Survey 

CM Continuous Measurement 

CPI Consumer Price Index 

CPS Current Population Survey 

HUD Department of Housing and Urban Development 

ICPE Intercensal Population Estimates 

NAS National Academy of Sciences 

OMB Office of Management and Budget 

This is a work of the U.S. government and is not subject to copyright protection in the 

United States. It may be reproduced and distributed in its entirety without further 

permission from GAO. However, because this work may contain copyrighted images or 

other material, permission from the copyright holder may be necessary if you wish to 

reproduce this material separately. 
Page 1 GAO-05-82 American Community Survey 

October 8, 2004 

The Honorable Tom Davis, Chairman 

The Honorable Henry Waxman, Ranking Minority Member 

Committee on Government Reform 

House of Representatives 

The Honorable William Lacy Clay, Ranking Minority Member 

Subcommittee on Technology, Information Policy, Intergovernmental 

 Relations, and the Census 

Committee on Government Reform 

House of Representatives 

The Honorable Adam Putnam 

House of Representatives 

The Census Bureau has designed the 2010 Decennial Census around three 

new operations. One will replace the Census long-form questionnaire with 

the American Community Survey (ACS).1

 Testing the ACS began in 1996 

and full implementation will begin in 2005 and continue as long as the 

program receives annual funding. 

A separate long-form questionnaire has been mailed to a sample of 

households once a decade to collect detailed information on demographic, 

housing, social, and economic characteristics since the 1960 Decennial 

Census. This information has been the main source of information for 

small geographic areas, including tracts and block groups; it has been used 

extensively by federal agencies for program implementation and by state 

and local governments for programmatic and planning purposes. In the 

2000 Decennial Census, the long form was mailed to a sample of about 

19 million housing units. 

The ACS will contain the same questions as the long form but will be 

mailed monthly to an annual sample of 3 million housing units. With the 

smaller sample, the ACS is designed to provide the same information at 

 1

We discuss the other operations, which relate to the address list and the short-form 

census, in full in GAO, 2010 Census: Cost and Design Issues Need to Be Addressed Soon, 

GAO-04-37 (Washington, D.C.: Jan. 15, 2004). 

United States Government Accountability Office

Washington, DC 20548 
Page 2 GAO-05-82 American Community Survey 

the same level of geographic detail as the long form by means of a 

continuous measurement methodology in which survey responses will be 

accumulated over time. The Census Bureau has determined that in order 

to produce reliable estimates at the same geographic level of detail as the 

long form, ACS results will be cumulated over 5 years. It also has 

determined that the ACS will provide reliable estimates for geographic 

areas with populations of 20,000 to 65,000 by cumulating ACS responses 

over 3 years and for geographic areas with populations of more than 

65,000 by cumulating ACS results for 1 year but that these estimates will 

be less reliable than the corresponding long-form estimates. 

According to the plan the Congress approved, the first annual ACS data for 

geographic areas with populations larger than 65,000 will be published 

beginning in 2006 with data for 2005; 3-year averages for geographic areas 

with populations between 20,000 and 65,000 will begin in 2008; and 5-year 

averages for geographic areas with populations smaller than 20,000, 

including tracts and block groups, will begin in 2010. The 5-year averages 

for 2008–12 to be published in 2013 will replace the 2010 Decennial Census 

long form for small geographic areas, as they will be centered on 2010 and 

closely reflect the population and housing characteristics data from the 

2010 Decennial Census short form. In replacing the long form, the ACS will 

provide the same long-form data items at the same level of geographic area 

detail but in a more timely way. Whereas the long form provided small 

geographic detail once a decade, the ACS will provide annual estimates for 

large geographic areas and estimates for smaller areas in terms of 3-year 

or 5-year averages. 

You asked us to examine issues about replacing the long form with the 

ACS related to the reliability of data for small geographic areas. As agreed 

with your offices, our objectives for this report were to (1) review the 

Census Bureau’s testing program on operational and programmatic 

aspects that will affect the reliability of small geographic area data and 

(2) determine whether alternatives to the proposed ACS would provide 

more frequent and more reliable data for small geographic areas. 

To address these topics, we reviewed ACS-related Census Bureau 

documents, congressional testimony, National Academy of Sciences (NAS) 

reports, and consultants’ reports prepared for the Census Bureau, Bureau 

of Labor Statistics (BLS), and Department of Housing and Urban 

Development (HUD). We also interviewed small-area data experts on the 

latest NAS report on the ACS and reviewed the Census Bureau’s responses 

to recommendations on the ACS in our earlier reports. 
Page 3 GAO-05-82 American Community Survey 

We conducted our work between April 2003 and August 2004 in 

accordance with generally accepted government auditing standards. We 

describe our scope and methodology in more detail in appendix I. 

If the ACS is to be an adequate replacement for the Decennial Census long 

form as the major source of data on small geographic areas and if it is to 

provide similar annual data for larger areas, we believe that the Census 

Bureau will need to (1) incorporate in a timely manner the resolution of 

issues it has already identified in testing the ACS, (2) complete the ACS 

evaluation and testing plan to identify other issues and provide 

information for users that will be necessary for the transition to the full 

ACS, (3) evaluate issues identified in this report and consult with 

stakeholders and users on their resolution, (4) coordinate the results of 

the testing program for the 2010 Decennial Census short form with the 

ACS implementation schedule, and (5) resolve all issues so that the ACS 

estimates beginning with 2008 are consistent with the ACS estimates for 

2009–12 and with the 2010 Census short form. 

Unresolved issues that might affect the reliability of ACS small geographic 

area data include (1) the introduction of a new concept of residence, 

(2) the uncertainty about the new methodology for deriving independent 

controls for population and housing characteristics, (3) the lack of 

guidance for users from the Census Bureau on the characteristics of 

multiyear averages for small geographic areas, and (4) operational 

procedures, such as questionnaire design and the adjustment to dollardenominated values, and to the consistency between ACS and 2000 Census 

long-form data. 

The Census Bureau has announced that it will adopt a concept of “current 

residence” for determining the geographic location of seasonal residents 

for the full ACS. The concept will differ from “usual residence,” used for 

decennial censuses and the ACS testing programs. Under the usual 

residence concept, people who spend their winter in Florida and the rest 

of the year in New Hampshire, for example, are recorded as residents of 

New Hampshire; college students living away from home in dormitories 

are recorded as residents of the college. Under the current residence 

concept, people have only one residence at any point in time, but their 

place of residence does not have to be the same throughout the year. 

Although the Census Bureau plans to change this concept for the ACS, it 

has reported that sufficient research has not been conducted to make a 

final set of rules for determining current residence. In addition, it found 

Results in Brief 

Key Unresolved Issues 
Page 4 GAO-05-82 American Community Survey 

problems with the residence questions used in 2000 but does not plan to 

incorporate improved questions until 2010. 

To determine independent controls for population and housing 

characteristics, which will be used to adjust ACS sample results, the ACS 

will use the characteristics derived from decennial censuses for the census 

year and for other years from the Census Bureau’s Intercensal Population 

Estimates (ICPE) program. The Census Bureau has not developed a 

methodology for using ICPE for the full ACS to derive controls consistent 

with the ACS residence concept and ACS reference period or at the same 

level of geography used for the 2000 Census long form. 

Before data for 2005 on places with populations of 65,000 or more can be 

released in 2006, a methodology is needed to provide controls that reflect 

changes in the residence concept and reference period. A methodology for 

controls for places with populations of more than 20,000 that incorporates 

ICPE revisions is needed before the first multiyear averages are released 

in 2008. In addition, if the averages for 2008–12 are to replace the 

2010 Census long form, the methodology for incorporating 2010 Census 

data and the related revisions to ICPE data will be needed in 2009. 

ACS data for geographic areas with populations smaller than 65,000 will be 

presented only in terms of multiyear averages. Because of the statistical 

properties of these averages and users’ unfamiliarity with them, we found 

that it is critical for the Census Bureau to provide users with guidance on 

topics such as the reliability of multiyear averages for areas with rapidly 

changing populations, the reliability of trends calculated from annual 

changes in multiyear averages, and the use of multiple estimates from the 

ACS data for geographic areas with populations larger than 20,000. Census 

Bureau officials told us that they agreed with the need for such guidance 

but had no plans for its contents. 

We found that the latest schedule for the 2010 Decennial Census does not 

provide adequate time for the Census Bureau to incorporate into the full 

ACS program changes necessary for the ACS data for 2008–12 to be 

reliable enough to replace the 2010 Census long form. We identified issues 

that need to be resolved before the 2006 release of the 2005 ACS and other 

issues that need to be resolved before the release of the first 3-year 

averages in 2008. The most important issues to be resolved are those that 

need to be in place by 2008, when the collection of data for calculating the 

5-year averages (for 2008–12) that will replace the 2010 Census long form 

will begin. Prompt resolution of the other issues would improve 

User Guidance on Multiyear 

Averages 

ACS Implementation Schedule 
Page 5 GAO-05-82 American Community Survey 

consistency between the 2005–07 ACS data and the ACS data beginning 

with 2008. 

Besides the key unresolved issues discussed above, we also identified an 

alternative to the proposed ACS that would provide more timely and 

reliable small geographic area data. This alternative would require 

additional funding to support a larger sample. Under an alternative, 

patterned after the Census Bureau’s initial plan to replace the 2000 Census 

long form, the sample size for 2009–11 would be increased to 4.8 million 

housing units and then reduced to 3.0 million housing units for subsequent 

years. The larger sample would provide small geographic area data that 

would be the replacement for the 2010 Census long form from 3-year 

averages (for 2009–11). These averages would be as reliable as the 

proposed 5-year averages (for 2008–12) and would provide the 

replacement for the long form data 1 year earlier. The larger sample could 

also be used permanently after 2011 and would provide continuous 3-year 

averages for small geographic areas. 

In written comments on a draft of this report, the Secretary of Commerce 

addressed three of the four recommendations we addressed to him. 

Regarding the first recommendation, the Secretary stated that the current 

ACS testing and evaluation plan already included the issues we have 

identified in the report. In following up to the Secretary's response, we 

learned that there is not yet a written plan, but only a rough outline of the 

types of work planned. Therefore, we believe our recommendation 

remains valid. Regarding the second recommendation, suggesting that the 

Census Bureau provide key stakeholders more direct and timely input into 

decisions on these issues, the Secretary stated that he believes that the 

present consultation process is adequate. We disagree, because as noted 

in appendix II of our report, the Census Bureau has not been responsive to 

recommendations from several National Academy of Sciences reports 

relating to the ACS. The Secretary agreed with our third recommendation 

that the Census Bureau provide public documentation for key decisions on 

issues we have identified in this report. The Secretary did not respond 

directly to our recommendation that he direct the Census Bureau to 

prepare a schedule for the 2010 Census that ensures that all necessary 

changes are made in time for the 2008 ACS so the 5-year ACS averages for 

2008–2012 will be an adequate replacement for the 2010 long form for 

small geographic areas. 

The comments from the Secretary also include a list of detailed technical 

comments from the Census Bureau. We reviewed each of these comments 

and revised the report where appropriate. 

Alternatives to Improve Small 

Geographic Area Data 
Page 6 GAO-05-82 American Community Survey 

Now that the Census Bureau has congressional approval to begin the full 

ACS, data collection will begin in November 2004. The ACS test survey of a 

sample of 800,000 housing units, which has been conducted since 2000, 

will end in December 2004. The Bureau has been using this survey, known 

as the ACS Supplementary Survey, to test procedures and to produce 

annual data for geographic areas with populations of 250,000 or more. As 

one part of the test program, the supplementary survey data for 2000 have 

been compared with corresponding data from the 2000 Census long form 

to evaluate the quality of the ACS data and to provide users with 

information to make the transition from the long-form data to the full ACS 

data. According to the plan the Congress approved, the first annual ACS 

data for geographic areas with populations larger than 65,000 will be 

published beginning in 2006 with data for 2005; 3-year averages for 

geographic areas with populations between 20,000 and 65,000 will begin in 

2008; and 5-year averages for geographic areas with populations smaller 

than 20,000, including Census tracts and block groups, will begin in 

2010. The 5-year averages for 2008–12 will replace the 2010 Decennial 

Census long form for small geographic areas; they will be published in 

2013 and will incorporate population and housing characteristics data 

from the 2010 Decennial Census short form. 

In replacing the long form, the ACS will provide the same long-form data 

items at the same level of geographic area detail but in a more timely way. 

Whereas the long form provided small geographic detail once a decade, 

the ACS will provide annual estimates for large geographic areas and 

estimates for smaller areas in terms of 3-year or 5-year averages; the 5-year 

averages will provide data at the same geographic area level as the long 

form. According to the Census Bureau, these 5-year averages will be about 

as accurate as the long-form data; the annual and 3-year averages will be 

significantly less reliable than the long-form data but more reliable than 

existing annual household surveys the Census Bureau conducts.2

In the remainder of the Background section of this report, we briefly 

describe the major differences between the ACS and the Decennial Census 

long form. We also discuss the Census Bureau’s outreach program, 

designed to involve stakeholders and users in shaping the ACS. Appendix 

III provides additional background information on the evolution of the 

 2

We discuss the relative quality of the ACS and the long form in GAO, The American 

Community Survey: Accuracy and Timeliness Issues, GAO-02-956R (Washington, D.C.: 

Sept. 30, 2002), pp. 8–13. 

Background 
Page 7 GAO-05-82 American Community Survey 

ACS plan, appendix IV on the ACS testing and measurement program. 

Appendix II describes recent NAS findings on Continuous Measurement 

(CM) and the ACS. 

The 2000 Census long form used a decennial sample of about 19 million 

housing units; the full ACS will use an annual sample of 3 million housing 

units. In order to provide reliable estimates for geographic areas with 

populations of 65,000 or less, monthly ACS responses will be cumulated 

over several years—3 years for places with populations of 20,000 to 

65,000 and 5 years for places with populations smaller than 20,000. 

Because of the statistical properties of these averages and users’ 

unfamiliarity with them, the Census Bureau has long recognized the need 

to provide guidance on such topics as the reliability of the averages for 

areas with rapidly changing population and the use of multiple estimates 

for states and other, larger geographic areas. 

For the 2000 Decennial Census, the ACS test programs, and federal 

household surveys, including the Current Population Survey (CPS), 

seasonal residents are recorded in a geographic area according to a 

concept of usual residence. As we noted above, under this concept, people 

who spend their winter in Florida and the rest of the year in New 

Hampshire, for example, are recorded as residents of New Hampshire; 

college students living away from home in dormitories are recorded as 

residents of the college. 

For the full ACS, the Census Bureau has announced its decision to change 

the concept to current residence. According to the Census Bureau, 

although each concept requires that a person have only one residence at 

any point in time, current residence recognizes that the place of residence 

does not have to be the same throughout a year, allowing ACS data to 

more closely reflect the actual characteristics of each area. The Census 

Bureau plans to use current residence because the ACS is conducted every 

month and produces annual averages rather than point-in-time estimates, 

unlike the Decennial Census. Current residence is uniquely suited to the 

ACS, because it continuously collects information from independent 

monthly samples throughout all months of all years. Because the ACS is 

designed to produce a continuous measure of the characteristics of states, 

counties, and other places every year, the new residence rules were 

needed for seasonal and migratory individuals. 

Multiyear Averages 

The Concept of Residence 
Page 8 GAO-05-82 American Community Survey 

The underlying population and housing characteristics data for the 

2000 Census long form were for April 1, 2000. For the ACS test program, 

the underlying population and housing characteristics varied. For all years 

except 2000, they were for July 1; for 2000, they were for April 1. For the 

full ACS, because the data are collected monthly, the reference period will 

be the average for the year, and the Census Bureau will assume this 

average is equivalent to data for July 1. 

The ACS will use population characteristics (age, sex, race, and ethnicity) 

and housing characteristics (occupied and vacant units) derived from an 

independent source and not from the results collected in the survey. Using 

independent controls for these characteristics is standard practice to 

correct sample survey results for the effects of nonresponse and 

undercoverage. Population and housing characteristics from the 

2000 Census short form were used as independent controls for the 

2000 Census long form, down to the tract level. For the ACS 

supplementary surveys, independent controls were from ICPE, which uses 

Decennial Census short-form data as benchmarks and administrative 

record data to interpolate between and extrapolate from the census 

benchmarks. ICPE develops and disseminates annual estimates of the total 

population and the distribution by age, sex, race, and Hispanic origin for 

the nation, state, counties, and functioning government units. ICPE 

provides annual estimates of population and housing characteristics at the 

county level, and for some subcounty levels, as of July 1, using the usual 

residence concept for seasonal residents. 

According to current Census Bureau plans, annual estimates of dollardenominated data items, such as income, rent, and housing-related 

expenses, will be presented after adjustment for inflation in order to 

facilitate comparisons over time. As in the ACS test programs, only annual 

estimates with this adjustment will be presented. The Census Bureau also 

has decided to continue to adjust annual data collected each month in the 

ACS to a calendar year basis. It will be using the Consumer Price Index 

(CPI) for the annual and monthly adjustments for all geographic areas.3

 3

The CPI is a national-level price index that BLS compiles. It also compiles separate price 

indexes for selected geographic areas, but these indexes do not measure differences in the 

level of prices among areas. 

Reference Period 

Independent Controls for 

Population and Housing 

Characteristics 

Dollar-Denominated Data 

Items 
Page 9 GAO-05-82 American Community Survey 

The long form and ACS will also differ in how operations are conducted, 

such as nonresponse follow-up and data capture. For the 2000 Census long 

form, nonresponse follow-up was conducted for all nonrespondents. For 

the ACS supplementary surveys and for the full ACS, nonresponse followup will be conducted for a sample of one-third of all nonrespondents. For 

the 2000 Census long form, all data items were entered using automated 

optical character recognition procedure; data from the ACS will be 

manually keyed. 

The ACS supplementary surveys excluded persons living in group 

quarters. Group quarters—which include nursing homes, prisons, college 

dormitories, military barracks, institutions for juveniles, and emergency 

and transitional shelters for the homeless—accounted for roughly 

2.8 percent of the population in 2000. The Census Bureau decided not to 

cover these persons in the supplementary surveys, to avoid duplication 

with the 2000 Census, and because it lacked funding to cover them in 

subsequent years. Procedures for including in the ACS persons living in 

group quarters beginning with 2005 are discussed in the Census Bureau’s 

ACS Operations Plan, issued in March 2003.4

 In addition, it has announced 

that it intends to continue testing procedures to improve the mailing list 

for group quarters to be used for the 2010 Decennial Census. 

The Census Bureau has long recognized the need to seek input from 

stakeholders and users in making decisions for all its programs. The 

Census Bureau sponsors technical reports that NAS prepares. (In 

appendix II, we summarize recent NAS reports on the ACS and related 

decennial censuses.) The Census Bureau has also held conferences on the 

ACS and has contracted with Westat Inc. to organize two conferences of 

experts on specific aspects of the ACS. Additionally, the Census Advisory 

Committees, which are Census Bureau–appointed advisory committees 

whose members represent professional associations such as the American 

Statistical Association (ASA) and the American Marketing Association, 

meet twice a year. The Census Bureau and other federal statistical 

agencies also participate in the quarterly meetings of the Council of 

Professional Associations on Federal Statistics, whose members include 

 4

U.S. Census Bureau, American Community Survey Operations Plan, Release 1 

(Washington, D.C.: March 2003), pp. 52–53. 

Operational Differences 

Group Quarters 

Outreach 
Page 10 GAO-05-82 American Community Survey 

professional associations, businesses, research institutes, and others 

interested in federal statistics.5

To obtain input from other federal agencies, the Office of Management and 

Budget (OMB) established an interagency advisory committee for the ACS 

in 2000. The committee’s major purpose was to coordinate the review of 

questions to be included in the ACS. Because of the committee’s limited 

focus, the Census Bureau established the ACS Federal Agency Information 

Program in 2003, responding to a recommendation we made.6 This 

program is designed to assist each federal agency that has a current or 

potential use for ACS data to achieve a smooth transition to using the ACS. 

From its beginnings in the mid-1990s, the Census Bureau’s development 

plan for the ACS was designed to ensure that the ACS would satisfactorily 

replace the Decennial Census long form as the major source of small 

geographic area data. In our review of the plan, we found that the Census 

Bureau, as well as key ACS stakeholders, had for many years identified the 

key issues that needed to be resolved if the ACS were to reach this goal. 

We have identified the following unresolved issues from our research 

(described in appendix I): 

• the methodology to be used for deriving independent controls for 

population and housing characteristics with ACS definitions of place of 

residence and reference date, 

• improvements needed to operational procedures, 

• methods for valuation and presentation of dollar-denominated data items, 

• comprehensive analysis of the comparability between new ACS data and 

corresponding data from the 2000 Census long-form and 2004 

supplementary survey, and 

• the provision of user guidance on multiyear averages. 

 5

This group’s objective is to provide an open dialogue between its members and federal 

statistical agencies. See Council of Professional Associations on Federal Statistics, 

http://www.copafs.org (May 10, 2004). 

6

See our recommendations in GAO-02-956R, pp. 25–26. For information on the Federal 

Agency Information Program, see Census Bureau, American Community Survey, 

http://www.census.gov/acs/www (May 10, 2004). 

Outstanding Issues 

Jeopardize ACS’s 

Replacement of the 

Long Form 
Page 11 GAO-05-82 American Community Survey 

Despite the Census Bureau’s early identification of issues critical to the 

successful replacement of the 2010 Decennial Census long form as the 

new source of small geographic area data, we found that its plans to 

resolve these issues have been only partially completed. Furthermore, we 

found that despite recent changes to the ACS implementation schedule, it 

is not fully synchronized with the Census Bureau’s time schedule for 

implementing the testing program for the 2010 Decennial Census. 

Consequently, if these issues are not resolved in a timely manner, the 

Census Bureau’s plan to replace the 2010 Decennial Census long form with 

the 2008–12 ACS averages for detailed geographic areas will be 

jeopardized. 

It is standard practice to use independent controls for population and 

housing characteristics to correct the results of sample surveys for the 

effects of nonresponse and undercoverage. For the 2000 Census long form, 

characteristics from the 2000 Census short form were used as independent 

controls down to the tract level. For the annual ACS supplementary 

surveys, characteristics from ICPE were used as the independent 

controls.7

Independent controls for the full ACS will require a new methodology. 

Short-form data are available only once every 10 years, and the annual 

ICPE estimates do not provide data for the detailed geographic areas 

needed to prepare long-form detail and do not use the ACS residence 

concept or reference period. The new methodology is critical to the 

reliability of the ACS estimates of small geographic areas that ICPE does 

not provide and of areas that have large numbers of seasonal residents. 

Census Bureau staff have long recognized the need for the new 

methodology. For example, a 1995 paper by Love, Dalzell, and Alexander 

expressed concern about population controls and residence rules as well 

 7

ICPE develops and disseminates annual “official” estimates of the total population and the 

distribution by age, sex, race, and Hispanic origin for the nation, state, counties, and 

functioning government units. The program is authorized by 13 U.S.C. §181, which requires 

the production of “current data on total population and population characteristics.” The 

estimates of population and housing characteristics are as of July 1 of each year, using the 

usual resident concept for seasonal residents. For details on subcounty estimates, see U.S. 

Census Bureau, “Estimates and Projections Area Documentation: Subcounty Total 

Population Estimates,” http://www.census.gov. 

A Methodology for 

Independent Controls for 

Population and Housing 

Characteristics Is Lacking 
Page 12 GAO-05-82 American Community Survey 

as the need for consultation with users on these topics.8 They reported that 

the Census Bureau was planning to conduct research using data from the 

1996 test sites to produce controls at the census tract and block group 

levels. They also noted that the Census Bureau would need to conduct 

research on the residence rule. A 2000 paper by Alexander and Wetrogan 

also discussed the issue of population controls.9 They reviewed possible 

methods for using ICPE to develop controls for the ACS and noted the 

need to consult with users on how to present information on the 

differences in ACS controls and ICPE in ACS publications. 

Key stakeholders, including experts on the ACS we interviewed in August 

2003 (listed in appendix I), expressed similar concerns about the 

methodology. 

It appears that no progress had been made on a new methodology until the 

Census Bureau reported in October 2003 to its advisory committees on the 

status of a new methodology to derive controls. It announced that when 

full ACS collection starts in November 2004, (1) interim procedures would 

be used and (2) a final methodology would not be determined until after 

the necessary research was completed. The Census Bureau did not 

provide a date when the methodology would be incorporated. 

In our review of Census Bureau presentations about the new methodology 

(described in detail in appendix V), we found that it had no plans to 

maintain time-series consistency of the population and housing controls 

by routinely incorporating the regular revisions to ICPE estimates into the 

ACS. Without such revisions, there could be a significant lack of 

comparability in the ACS data being averaged, and the reliability of 

multiyear estimates would be reduced. For example, without such 

revisions, the 2008–12 averages that are to replace the 2010 Decennial 

Census long form would be based on controls extrapolated from the 

2000 Census for 2008–09 and controls from the 2010 Census for 

2010–12. In addition, time-series consistency in the annual ACS data would 

be reduced, especially in the data for 2010 and previous years. Census 

 8

Susan Love, Donald Dalzell, and Charles Alexander, “Constructing a Major Survey: 

Operational Plans and Issues for Continuous Measurement,” presented at the annual 

American Statistical Association meeting, Orlando, Florida, August 1995. 

9

Charles H. Alexander and Signe Wetrogan, “Integrating the American Community Survey 

and the Intercensal Demographic Estimates Program,” presented at the Joint Statistical 

Meetings, Indianapolis, Indiana, August 14, 2000. 
Page 13 GAO-05-82 American Community Survey 

Bureau officials told us that they were not planning any such revisions, 

unless the inconsistencies between 2010 ICPE and 2010 Census 

characteristics were significant, even though there were significant 

inconsistencies between the 2000 ICPE estimates and the 2000 Census 

data, especially for small geographic areas. 

We found that regularly incorporating all revisions to ICPE into the ACS 

would improve ACS reliability and that planning would give users advance 

notice on the Census Bureau’s revision practice. The need for such 

planning is critical, as evidenced by the failure that occurred in January 

2004, when a revised set of ICPE data was incorporated into the 

calculation of monthly CPS data on employment. Initially, the revised 

employment estimates were released without a revision of the 

pre-2004 data, resulting in a significant discontinuity between December 

2003 and January 2004. As a result of users’ dissatisfaction about the 

discontinuity, a consistent set of employment estimates was released.10

Finally, failure to adequately involve stakeholders in the decision process 

may contribute to significant misunderstanding about the use of the ACS 

estimates and corresponding estimates from the Decennial Census. In past 

decennial censuses, except for the very smallest geographic areas, the 

population and housing characteristics data published as part of the longform detail were the same as the official data based on data collected on 

the short form. Because of differences in the residence and reference 

period concepts and the use of multiyear averages for small geographic 

areas, there will be less consistency between the ACS averages for 

2008-12 and the 2010 Census data. 

The Census Bureau has identified operational issues with the ACS test 

programs, primarily from its evaluation studies on the 2000 Decennial 

Census and Census Bureau staff research papers on comparisons between 

data collected in the ACS 2000 Supplementary Survey and the 2000 

Decennial Census long form. These issues (described in detail in appendix 

V) include problems with questionnaire design, nonresponse followup, and 

data capture, as well as coverage of persons living in group quarters. 

 10See Bureau of Labor Statistics, “Labor Force and Employment Estimates Smoothed for 

Population Adjustments, 1990–2003,” Washington, D.C., March 3, 2004. U.S. Department of 

Labor, Bureau of Labor Statistics, Demographics, Demographic Characteristics of the 

Labor Force (Current Population Survey), http://www.bls.gov/cps/cpspopsm.pdf (May 10, 

2004). 

Operational Issues Have 

Not Been Addressed 
Page 14 GAO-05-82 American Community Survey 

For example, the Census Bureau conducted a study to evaluate the design 

of the ACS questions that are needed to implement the residence concept 

and reference period for the ACS.11 The study suggested that additional 

testing was needed for the questions about multiple residences and noted 

“that asking these questions on a person basis may produce different and 

probably better data than asking them on a household basis.”12 Similarly, 

the authors found potential problems with the identification of seasonal 

residents. We were not able to identify in the Census Bureau’s plans 

whether these issues would be addressed before implementation of the 

full ACS. 

We also found, for the implementation of the full ACS for 2005, that the 

Census Bureau had addressed only the inclusion of group quarters and 

that it may not resolve the issue of questionnaire design until 2010. In 

addition, even for group quarters, it is planning for improvements that may 

not be included until 2010. Furthermore, not all problems have been 

identified because of the delays in the Census Bureau’s completing the 

evaluation studies of comparisons of long-form and ACS data items. 

Moreover, the Census Bureau’s plans do not provide for external 

consultations on key decisions about resolving issues. 

Although the Census Bureau has acknowledged the importance of the 

timing of incorporating changes to resolve the various issues, any delay in 

implementing solutions to 2010 would not meet the needs of the ACS 

collection and production schedule. For example, in its March 2003 ACS 

operations plan, the Census Bureau recognized the need for maintaining 

questionnaire continuity to calculate consistent multiyear averages. It also 

has reported that it needs to incorporate changes in the ACS questionnaire 

no later than 2008 because changes introduced after 2008 and before 

2013 would create inconsistencies in calculating the 5-year averages that 

are to replace the 2010 Decennial Census long form. Nevertheless, we 

found that the Census Bureau’s current time schedule does not call for 

resolving issues such as questionnaire design before 2008. 

Incorporating changes into the ACS beginning with 2008 will help maintain 

the reliability of the 5-year averages for small geographic areas; failing to 

 11Theresa J. DeMaio and Kristen A. Hughes, “Report of Cognitive Research on the 

Residence Rules and Seasonality Questions on the American Community Survey,” U.S. 

Census Bureau, Statistical Research Division, Washington, D.C., July 2003. 

12DeMaio and Hughes, pp. 9–10. 
Page 15 GAO-05-82 American Community Survey 

incorporate them beginning with 2005 will reduce the reliability of the 

annual changes in the ACS data. 

With regard to external consultation, we found that the Census Bureau’s 

plans do not include time for consulting with stakeholders and users, 

despite NAS, BLS, and Census Advisory Committee suggestions and 

recommendations. For example, in a February 15, 2001, report to the 

Census Bureau, the NAS Panel on Research on Future Census Methods 

recommended that it conduct evaluation studies on “the effectiveness of 

operations used to designate special places and enumerate the group 

quarters and homeless populations.”13 Members of the Census Advisory 

Committee had raised similar concerns. In a 2003 report prepared for BLS, 

their consultant had made a number of recommendations about the 

questions on employment. 

We found that the Census Bureau needs to develop a time schedule so that 

changes can be introduced to minimize inconsistencies between the 

2005 and subsequent ACS data and to ensure that all necessary changes 

are made so that the ACS data for 2008–12 that will replace the 2010 

Decennial Census long form will be collected consistently. In addition, the 

prompt completion of the ACS—long-form comparison studies and related 

evaluations will provide sufficient time for the Census Bureau to consult 

with stakeholders and to provide users with the information they need to 

understand the effect of making changes to the ACS questionnaires or 

procedures between 2005 and 2008. 

When the Census Bureau began releasing data from the ACS test 

programs, all dollar-denominated items such as incomes, housing values, 

rents, and housing-related expenditures were adjusted for inflation. As in 

the ACS test programs, only annual estimates with this adjustment will be 

presented, and when the Census Bureau releases ACS data for each new 

year, it revises all dollar-denominated data for prior years. It makes a 

similar inflation adjustment for the annual income data collected in the 

 13Benjamin F. King, Chair, Panel on Research on Future Census Methods, National 

Academy of Sciences, letter to William Barron, Acting Director, U.S. Bureau of the Census, 

Washington, D.C., February 15, 2001, pp. 3–4. The National Academies, National Academies 

Press, 2010 Census Panel Letter Report (2001), 

http://books.nap.edu/html/2010_census_panel/letterreport.pdf (May 10, 2004). 

Plans for Valuation and 

Presentation of DollarDenominated Data Items 

Are Questionable 
Page 16 GAO-05-82 American Community Survey 

CPS, but it releases the unadjusted estimates.14 The Census Bureau also 

has decided to continue to adjust annual data collected each month in the 

ACS to a calendar year basis. It will be using the CPI for the annual and 

monthly adjustments for all geographic areas. 

The treatment of dollar-denominated data items is critical to all users of 

these data. It is particularly critical for federal agencies that will be using 

the ACS instead of the long form for many government programs to 

determine the allocation of funds or program eligibility. It is also critical to 

users of dollar-denominated items for small geographic areas because the 

inflation adjustments under the current procedure are based on a national 

average index. 

In our review of the development and implementation of the ACS, we 

identified questions on the appropriateness of the methodology for the 

adjustment and the suppression of the unadjusted annual values. A report 

prepared for HUD found problems with the calculation of the adjustment 

and the use of the adjustment for income measures used for HUD 

programs. The report also noted that the lack of the unadjusted annual 

data would severely limit HUD’s use of calculations appropriate to its 

program needs. Research by Census Bureau staff questioned the 

adjustment for incomes when they found that it was a probable source of 

difference between income data from the supplementary survey and 

corresponding data from the CPS and the 2000 Census long form.15 (We 

discuss these findings in detail in appendix V.) 

Our statisticians reviewed these findings and found a similar problem with 

the calculation of the adjustment because of the lack of trending 

adjustment. We found that the Census Bureau could estimate calendar 

year values using a combination of past trends in related series, 

information from other ACS respondents, or known information such as 

changes in cost-of-living adjustments for various transfer payment 

programs and changes in wage rates. We also found that converting ACS 

 14BLS makes a similar adjustment to the average weekly earnings data from the monthly 

establishment survey. 

15For the HUD report, see ORC Macro, The American Community Survey: Challenges and 

Opportunities for HUD (Calverton, Md.: Sept. 27, 2002). For a complete discussion of the 

role of the inflation adjustment in differences between the ACS and CPS measures of 

income, see Kirby G. Posey, Edward Welniak, and Charles Nelson, “Income in the ACS: 

Comparisons to Census 2000,” presented at the Joint Statistical Meetings, San Francisco, 

California, August 7, 2003. 
Page 17 GAO-05-82 American Community Survey 

data from monthly to calendar year data is similar to conversion issues 

faced by other agencies that collect annual statistics compiled on a fiscalyear basis and that the procedures these agencies use could be adapted for 

the ACS.16 With regard to the use of a national cost-of-living adjustment, 

we have previously reported that for purposes such as allocating federal 

funds to states using income and poverty data, the CPI, a national measure 

of inflation, does not reflect variations in geographic areas.17 Census 

Bureau staff have reported similar findings.18

The HUD and Census Bureau findings and our review raise serious 

questions about the inflation adjustments. We found no documentation 

explaining the rationale for the adjustment for either the ACS or the CPS, 

where its use is limited to income data. Bureau officials informed us that 

alternative procedures had not been examined and that stakeholders or 

users had not been consulted on the adjustment. 

We noted above that one of the Census Bureau’s major justifications for 

the ACS test programs has been its comparing data collected in these 

programs, and corresponding data from the 2000 Decennial Census short 

and long forms, to identify operational problems. Another major 

justification for the ACS test programs has been the use of these 

comparisons, and comparisons with corresponding data from the CPS, to 

inform users in making the transition from the 2000 long form to the ACS. 

 16For the procedures the Internal Revenue Service and the Department of Labor use, see 

SOI 2000: Corporation Income Tax Returns (Washington, D.C.: September 2003). Internal 

Revenue Service, Tax Statistics, Statistics of Income, SOI Products and Services, 

Corporation Tax Statistics—Complete Report Publications, 

http://www.irs.gov/taxstats/article/0,,id=112834,00.html (May 10, 2004), and U.S. 

Department of Labor, Pension and Welfare Benefits Administration, Private Pension Plan 

Bulletin: Abstract of 1998 Form 5500 Annual Reports, no. 11 (Washington, D.C.: winter 

2001–02). http://www.dol.gov/ebsa/PDF/1998pensionplanbulletin.pdf (May 10, 2004). 

17For example, in GAO, Poverty Measurement: Adjusting for Geographic Cost-of-Living 

Difference, GAO/GGD-95-64 (Washington, D.C.: Mar. 9, 1995), we noted that experts 

generally agreed that it is appropriate to adjust state-level poverty counts for cost-of-living 

differences but that they differed on the most appropriate method of making such 

adjustments. In Medicaid Formula: Differences in Funding Ability among States Often 

Are Widened, GAO-03-620 (Washington, D.C.: July 10, 2003), we showed that using 

different cost-of-living adjustments at the state level significantly affected the amount of 

federal funding. 

18Charles Nelson and Kathleen Short, “The Distributional Implications of Geographic 

Adjustment of Poverty Thresholds,” U.S. Census Bureau, Housing and Household 

Economics and Statistics Division, Washington, D.C., December 2003. 

Evaluations of 

Comparisons Are 

Incomplete and Users Lack 

Information on ACS TimeSeries Consistency 
Page 18 GAO-05-82 American Community Survey 

Census Bureau Director Kenneth Prewitt emphasized the importance of 

transition needs in testimony to the Congress in 2000 when he reported 

the following about the ACS test programs: 

“These data will also contribute to a comparison with data from Census 2000 that is 

necessary because there are differences in methods and definitions between the census 

and the ACS. Moreover, decision makers will want to compare an area’s data to those from 

Census 2000. Comparisons using data from the operational test and from the 31 sites are 

essential to determine how much measured change between Census 2000 and future years 

of the ACS is real and how much is due to operational differences between the ACS and the 

census.”19

Despite acknowledging the importance of these comparisons, the Census 

Bureau’s publication of evaluations of the comparisons has been delayed, 

and their scope has been reduced in terms of levels, data items, and time 

period. The lack of information will create problems for ACS users who 

will be comparing the annual ACS data for 2005 (to be released in mid2006) with 2000 Decennial Census data or comparing annual ACS 

supplementary survey data beginning with 2000. 

In addition to delaying the release of the evaluation studies, the Census 

Bureau has reduced their scope. For the evaluations of ACS test site data, 

local experts did not participate in the evaluation of the comparisons for 

27 of the 31 test sites. For the 4 test sites that were studied by local 

experts, they did not cover subcounty local government units. For 

evaluations of ACS supplementary survey data, the Census Bureau has 

eliminated the analyses of comparisons between (1) the 2000 

supplementary survey and the 2000 long form for geographic areas with 

populations of 250,000 or more and (2) the supplementary surveys for 

2000–02 to corresponding data from the CPS. It has reduced the scope of 

its evaluation studies by also eliminating comparisons of single-year 

 19Kenneth Prewitt, Director, U.S. Bureau of the Census, before the U.S. House of 

Representatives, Committee on Government Reform, Subcommittee on the Census, 

Summary of House Hearing on ACS July 20, 2000, The American Community Survey: A 

Replacement for the Census Long Form? Serial 106-246 (Washington, D.C.: July 20, 2000). 
Page 19 GAO-05-82 American Community Survey 

estimates for most subnational areas and comparisons of data items such 

as financial characteristics of housing.20

NAS found that the Census Bureau has not placed sufficient priority on 

completing the necessary evaluation studies.21 Furthermore, we found that 

the Census Bureau does not have a plan that includes the timely 

completion of all the studies. Once the studies are complete, it will need to 

incorporate the findings into ACS operations, consult with stakeholders, 

and provide users with the information they need to make the transition 

from the long form to the ACS. The plan will be needed to ensure that as 

many changes as possible can be introduced before the first annual ACS 

estimates are published in 2006 and that all necessary changes are 

implemented before 2008. 

We found that the delays in completing the evaluations and their reduction 

in scope are likely to affect the use of the ACS in improving the small 

geographic area estimates of unemployment and poverty. For example, 

Labor uses the unemployment data extensively to administer a variety of 

federal programs. Several other departments use the poverty rates for 

similar purposes.22

One of the major differences between the ACS and the long form is that 

the ACS will provide data for geographic areas with populations smaller 

than 65,000 in terms of multiyear averages. Experts outside and inside the 

Census Bureau have identified serious issues regarding the statistical 

properties of multiyear averages and have recommended that the Census 

Bureau provide guidance to federal agencies and others on their use. We 

found that stakeholders have urged the Census Bureau for many years to 

provide guidance on the strengths and weaknesses of these averages. The 

most recent request for guidance on using multiyear averages came in the 

 20Census Bureau officials indicated that some of the delay in completing the planned 

evaluation studies may have resulted from the Census Bureau’s need to devote additional 

resources to completing the evaluation of the 2000 Census Accuracy, Coverage, and 

Evaluation program and to a survey to test the effect of conducting the ACS as a voluntary 

survey. 

21See Daniel L. Cork, Michael L. Cohen, and Benjamin F. King, eds., Planning the 2010 

Census: Second Interim Report (Washington, D.C.: National Academies Press, 2003), p. 99. 

22In Statistical Policy Directive 14, OMB designated the CPS as the official source of 

statistical measures of poverty. The U.S. Department of Health and Human Services also 

designated the CPS as the source of poverty measures for its programs in “Annual Update 

of the HHS Poverty Guidelines,” 67 Fed. Reg. 6931 (Feb. 14, 2002). 

Users Are Not Informed on 

Key Properties of 

Multiyear Averages 
Page 20 GAO-05-82 American Community Survey 

July 2003 report by the NAS Panel on Research on Future Census 

Methods: “The Census Bureau should issue a user’s guide that details the 

statistical implications of the difference between point-in-time and moving 

average estimates for various uses.”23 In the report’s executive summary, 

the panel also stated that “The Census Bureau must do significant work in 

informing data users and stakeholders of the features and the problems of 

working with moving average-based estimates.”24 It also expressed 

particular concern about the use of the multiyear (or moving) averages in 

fund allocation formulas. 

Stakeholders have requested guidance on topics such as (1) the reliability 

of multiyear averages for areas with rapidly changing populations, (2) the 

reliability of trends calculated from annual changes in multiyear averages, 

and (3) the selection of ACS data for geographic areas with populations 

larger than 20,000 for which there will be multiple estimates. The Census 

Bureau has recognized the need for such guidance but has not announced 

any information about its contents or when it might be available, even 

though the guidance is needed well in advance of the release of the first 

multiyear averages in 2008. 

We also found that plans for research to evaluate the statistical properties 

of multiyear averages are limited. The contracts to evaluate 3-year 

averages for the ACS test sites cover only averages for 1999–2001, with no 

comparisons with averages for 2000–02, 2001–03, or 1999–2003. In 

addition, the evaluation studies discussed earlier lack any time-series 

dimension, such as comparisons of the supplementary surveys with annual 

data from the CPS. Thus, it appears that the Census Bureau has missed the 

opportunity to test (1) distortion and stability in multiyear averages, 

(2) differences between multiple estimates for the same geographic areas, 

and (3) the use of annual ACS data for small geographic areas. 

We found that in recent years, the Census Bureau has used its outreach 

efforts with stakeholders and users primarily to gain support for the ACS. 

Although it also has solicited advice from NAS panels, advisory committee 

members, and experts at workshops and conferences on some of the 

issues we have identified in this report, there is no indication that the 

Census Bureau will be following this advice. (For additional information, 

 23Cork, Cohen, and King, pp. 99–100. 

24Cork, Cohen, and King, p. 6. 

Meaningful External 

Consultation on Key Issues 

Is Needed 
Page 21 GAO-05-82 American Community Survey 

see appendix V.) Likewise, it has not yet followed similar advice from us, 

other government agencies, or even its own staff. 

It has been more than a year since the Census Bureau announced, in 

March 2003, that it was looking into establishing an ACS partnership 

program that would involve advisory groups and expert panels to help it 

improve the program. We found that no such program has been 

established yet. Given that many key issues remain unresolved and that 

the Census Bureau has no plans to seek advice on resolving them, key 

aspects of the ACS will receive little or no input unless the Census Bureau 

revises its plans. 

In 1994, the Congress began to fund testing of the survey to replace the 

2000 Decennial Census long form, beginning with the 2000 Census. In 

reviewing the development of the ACS, we found that the Census Bureau 

was planning to replace the 2000 long form by starting the ACS program 

with an annual sample of 4.8 million housing units for 1999, 2000, and 

2001 and reducing the sample for subsequent years to 3 million.25 The 

larger sample would have provided 3-year averages for all small 

geographic areas for 2000 and would have provided data for the smallest 

geographic areas of the same quality as the traditional long form. In fiscal 

year 1998, plans to introduce the ACS to replace the census long form 

were delayed until after the 2000 Census was completed. 

When the Census Bureau submitted its plans in 1998 to replace the long 

form for the 2010 Decennial Census, a similar increase in sample size for 

2009–11 was not proposed. Thus, compared with the plans for 2000, data 

for small geographic areas for 2010 would be delayed by a year and would 

be based on 5-year averages. When we reviewed the previous plan and 

other alternatives to the proposed ACS that would provide more timely 

and reliable data for small geographic areas, we determined that the only 

viable alternative to the current plans would be to expand the sample size 

for 2009–11, as proposed earlier. 

 25See, for example, Charles Alexander, “A Prototype Continuous Measurement System for 

the U.S. Census of Population and Housing,” CM-17, presented at the annual meeting of the 

Population Association of America, Miami, Florida, May 5, 1994, and Harry A. Scarr, Deputy 

Director, Census Bureau, “Continuous Measurement,” Association of Public Data Users, 

Fredericksburg, Virginia, October 16, 1994. 

Improving Timeliness 

and Quality of Small 

Geographic Area Data 

Would Increase Costs 
Page 22 GAO-05-82 American Community Survey 

This expansion would allow the Census Bureau to publish data for 

geographic areas with populations smaller than 20,000 a year earlier, and it 

would provide more reliable small- area data than under the currently 

planned 5-year averages. In addition, if the Congress were to provide the 

additional funds for this alternative, an additional year would be available 

for the Census Bureau to resolve issues we have identified in this report by 

giving it until the collection of data for 2009 rather than for 2008. 

According to Census Bureau estimates, increasing the sample size for the 

3 years would add about $250 million to the estimated $500 million cost for 

the 3 years, using the smaller sample. 

The most recent Census Bureau schedule for implementing the ACS over 

the complete cycle of the 2010 Decennial Census was prepared in 

December 2003. Except for the completion of the questionnaire for the 

2008 ACS, the milestones do not cover the resolution of issues that it has 

already identified and issues we identify in this report. (See table 1.) 

Ideally, all these issues should be resolved before the first annual results 

of the full ACS sample are released. However, the Census Bureau has 

already announced that final plans for calculating independent population 

and housing controls with ACS residence and reference concepts will not 

be available for several years, the 2004 test plans for the 2010 Decennial 

Census will cover group quarters and residence rules, reports from the 

2004 tests will not be completed until 2005, and the 2006 test plans for 

2010 also cover group quarters. 

Resolving 

Outstanding Issues 

Needs a Time 

Schedule 
Page 23 GAO-05-82 American Community Survey 

Table 1: ACS Milestone Events and Unresolved Issues, 2004–13 

Fiscal 

quarter ACS milestone event Unresolved issue 

2004 

Q4 Expand the ACS sample to 250,000 addresses per 

month. 

(1) Residence rule to be used 

(2) Changes to operational procedures, questionnaire 

design, etc., based on analyses of differences between 

earlier ACS estimates and other sources such as 2000 

Census or on evaluation of 2000 Census data 

2005 

Q1 Submit proposed topics for 2008 ACS to Congress (1) Changes based on analyses of differences between 

earlier ACS estimates and other sources such as 2000 

Census or on evaluation of 2000 Census data 

(2) Consultation with stakeholders and users 

Q4 Publish 2004 ACS single-year results for all states and 

most areas with population 250,000+ 

(1) Information on degree of stability of year-to-year 

changes in 2000–04 ACS based on comparisons with 

corresponding data from CPS and other surveys 

(2) Release of dollar-denominated data items without 

adjustments for inflation and adjustment methodology 

2006 

Q1 Submit actual questions for 2008 ACS to Congress Changes to questions to reflect results of analysis of 

differences between ACS test data and 2000 Census longform data, evaluation of reporting in 2000 Census, and 

results of 2004 Census test 

Q4 Publish 2005 ACS single-year results for all geographic 

areas and population groups of 65,000+ 

(1) Methodology for calculating independent controls for 

population characteristics and housing units based on ACS 

definition of residence and reference period 

(2) Source of independent controls for geographic areas 

not covered by ICPE 

(3) Level of geographic detail to be released—for example, 

counties with population of less than 65,000 or 

incorporated places other than counties with population of 

65,000 or more 

(4) Information on consistency between 2004 and 2005 

results 

2007 

Q1 Determine final content for the 2008 ACS (1) Changes to questions to reflect results of analysis of 

differences between ACS test data and 2000 Census longform data, evaluation of reporting in 2000 Census, and 

results of 2004 and 2006 Census tests 

(2) Consultation with stakeholders and users 
Page 24 GAO-05-82 American Community Survey 

Fiscal 

quarter ACS milestone event Unresolved issue 

Q4 Publish 2006 ACS single-year results for all geographic 

areas with population groups of 65,000+ 

(1) See 2006 Q4 

(2) Guidance for users on statistical properties of multiyear 

averages to be released in 2008 and on use of single-year 

results and multiyear accumulations for same geographic 

area 

2008 

Q1 Implement content or methodology changes for 2008 

ACS data collection (first year of 5-year ACS 

accumulation to replace 2010 long form) 

(1) Consultation with stakeholders and users 

(2) Final decisions on 2010 Census short form 

Q4 Publish 2007 ACS single-year results for all geographic 

areas with population 65,000+, publish 3-year (2005–07) 

accumulation for all areas with population of 20,000+ 

(1) See 2006 Q4 

(2) Plans and procedures for 3-year ACS accumulation—

for example, revision to independent controls for previous 

years 

2009 

Q1 Complete 2008 ACS data collection Changes to operational procedures, such as sampling rate 

for nonresponse followup 

Q4 Publish 2008 ACS single-year results for all geographic 

areas with population 65,000+, publish 3-year (2006–08) 

accumulation for areas with population 20,000+ 

Updated guidance for users on statistical properties of 

multiyear averages to be released in 2009 and on use of 

single-year results and multiyear accumulations for same 

geographic area 

2010 

Q4 Publish 2009 ACS single-year results for all geographic 

areas with population 65,000+, publish 3-year (2007–09) 

accumulation for areas with population 20,000+, publish 

5-year (2005–09) accumulation for all areas 

(1) See 2008 Q4 

(2) Incorporation of revisions to independent controls for 

2005–08 

2011 

Q4 Publish 2010 ACS single-year results for all geographic 

areas with population 65,000+, publish 3-year (2008–10) 

accumulation for areas with population 20,000+, publish 

5-year (2006–10) accumulation for all areas 

(1) Incorporate revisions to independent controls beginning 

with 2005 for benchmarking to 2010 Census 

(2) Methodology for April 1 reference date for independent 

controls for 2010 Census 

2012 

Q4 Publish 2011 ACS single-year results for all geographic 

areas with population 65,000+, publish 3-year (2009–11) 

accumulation for areas with population 20,000+, publish 

5-year (2007–11) accumulation for all areas 

(1) See 2011 Q4 

(2) Reconcile differences between ACS and 2010 Census 

short form 

2013 

Q4 Publish 2012 ACS single-year results for all geographic 

areas with population 65,000+, publish 3-year (2010–12) 

accumulation for areas with population 20,000+, publish 

5-year (2008–12) accumulation for all areas 

(1) See 2010 Q4 

(2) Level of geographic detail from the 2010 Census to be 

used for independent controls similar to that used for the 

2000 Decennial Census 

Source: U.S. Census Bureau and GAO analysis. 
Page 25 GAO-05-82 American Community Survey 

In addition, the Census Bureau has announced that comparisons of 

2000 ACS and 2000 Census long-form data critical to the transition to the 

full ACS will be limited. Nevertheless, users who need the evaluation of 

these comparisons to compare data from the 2000 Decennial Census long 

form with data from the new ACS data or from the ACS supplementary 

surveys would benefit from the early resolution of other issues. For 

example, resolving issues before the release of the first 3-year averages 

(2005–07) would improve the consistency between these averages and the 

subsequent ACS data. Resolving all issues for the 2008 ACS is critical if 

these data are to be fully consistent with the ACS data for 2009–12 and the 

2008–12 averages are to be fully consistent with the 2010 Decennial 

Census short-form data. As we noted above, the Census Bureau’s schedule 

does call for timely completion of the 2008 questionnaire. However, if 

questions to be included in the 2010 Census short form are changed during 

the congressional and OMB approval processes, currently scheduled for 

2008 and 2009, data collected on the 2010 Census short form will be 

inconsistent with the ACS data. 

The Census Bureau’s development of the ACS goes back several decades 

and has included intensive research and field testing programs, as well as 

substantial outreach efforts, in particular through the reports and 

workshops at NAS. However, its current plan to begin full implementation 

of the ACS for 2005 has several critical deficiencies. The Census Bureau 

has not completed its testing program, and it has not acted to resolve key 

issues already identified by the ACS test program, by evaluation studies of 

the 2000 Decennial Census, by Census Bureau research studies, and by 

stakeholders and users, including us, NAS, and other federal agencies. 

Furthermore, the ACS implementation plan and the 2010 Decennial 

Census test programs are not synchronized, and there is no 

comprehensive program for external consultation on the resolution of 

these issues. Without prompt resolution of issues such as those relating to 

the calculation of independent controls for small geographic areas and the 

consistency of data used to calculate multiyear averages, the ACS will not 

be an adequate replacement for the long form in the 2010 Decennial 

Census. If the Census Bureau is not able to use the ACS to replace the long 

form, the Congress and other stakeholders need to be advised in 2005 in 

order to allow for the Census Bureau time to reinstate the long form for 

the 2010 Census.26

 26GAO-04-37, pp. 11–12. 

Conclusions 
Page 26 GAO-05-82 American Community Survey 

To ensure that the ACS is an adequate replacement for the Decennial 

Census long form, we recommend that the Secretary of Commerce direct 

the Census Bureau to (1) revise the ACS evaluation and testing plan and 

focus on the issues we have identified in this report; (2) provide key 

stakeholders, such as the National Academy of Sciences, with meaningful 

and timely input on decisions relating to these issues; and (3) make public 

the information underlying the Census Bureau’s decisions on these issues 

when it makes the decisions. We also recommend that the Secretary direct 

the Census Bureau to prepare a time schedule for the 2010 Decennial 

Census that provides for resolving these issues by incorporating all 

operational and programmatic changes into the 2008 ACS so that the 

5-year averages for 2008–12 will adequately replace the 2010 Decennial 

Census long-form data for small geographic areas. These revisions should 

be reflected in the single, comprehensive project plan for the 2010 Census, 

as we have previously recommended. 

In written comments on a draft of this report, the Secretary of Commerce 

provided comments on our recommendations. (The Secretary’s comments 

are reprinted in appendix VI.) He disagreed with our recommendation that 

the ACS evaluation and testing plan needed to be revised to focus on 

issues we have identified in this report, stating that the current ACS testing 

and evaluation plan already included these issues. In following up on the 

Secretary's response, we learned that there is not yet a written plan, but 

only a rough outline of the types of work planned. Therefore, we believe 

our recommendation remains valid. The Secretary did not accept our 

recommendation to provide key stakeholders more direct and timely input 

into decisions on these issues because he believes that the present 

consultation process is adequate. We disagree, because as noted in 

Appendix II of our report, the Census Bureau has not been responsive to 

recommendations from several National Academy of Sciences reports 

relating to the ACS. The Secretary agreed with the recommendation that 

the Census Bureau provide public documentation for key decisions on 

issues we have identified in this report. The Secretary did not respond 

directly to our recommendation that he direct the Census Bureau to 

prepare a schedule for the 2010 Census that ensures that all necessary 

changes are made in time for the 2008 ACS so the 5-year ACS averages for 

2008-2012 will be an adequate replacement for the 2010 long form for small 

geographic areas. 

The Secretary provided comments on the five major outstanding issues 

that, in our view, jeopardize the ACS as a replacement of the long form: 

lack of methodology for independent controls, operational issues not 

Recommendations for 

Executive Action 

Agency Comments 

and Our Evaluation 
Page 27 GAO-05-82 American Community Survey 

addressed, questionable plans for dollar-denominated items, incomplete 

evaluations and lack of information on ACS time-series consistency, and 

lack of information about multiyear averages. 

The Secretary disagreed with our findings about the lack of a methodology 

for independent population and housing controls. He stated that a 

methodology for the ACS was already in place. On the issue that changes 

to that methodology are needed to account for the difference in the ACS 

residence concept, the Secretary agreed that a change was needed but 

stated that it could be delayed for several more years. On the issue of 

independent controls for subcounty areas, he stated that the Census 

Bureau had no plans to develop such controls, which we found were used 

for the 2000 Census long form, but that it might develop such controls 

using data from the ACS or administrative records. However, he did not 

respond to our findings about the use of existing subcounty area data from 

the ICPE or from the 2010 Census short form. The Secretary stated that 

the Census Bureau also had no plans to revise the ICPE. On the issue of 

the ACS reference period, the Secretary reported that the Census Bureau 

had recently decided to assume that July 1 would be used as the reference 

period. The Secretary did not comment on GAO’s findings about the lack 

of plans to incorporate into the ACS 2010 Census data and related 

revisions to the ICPE estimates for previous years. 

We disagree with the Secretary’s comments about the independent 

subcounty population and housing controls and believe that their use in 

the ACS is needed for the ACS to be an adequate replacement for the 2010 

Census long form for small geographical areas. We found that independent 

controls from the 2000 Census short form were used for detailed 

geographic areas for the 2000 Census long form and that differences in 

counts of population and housing (occupied and vacant) between the long 

form and the short form were limited to the smallest geographic areas. 

The similar use of 2010 Census short-form counts in the ACS also would 

minimize differences in these counts from the ACS and the 2010 Census. 

Consequently, we disagree with the Bureau’s plan not to commit to the 

development of subcounty controls and its plans not to base these 

controls on ICPE total population and housing estimates, which are 

prepared annually for all general government units, and the more detailed 

and reliable data from the 2010 Census short form. 

We also disagree with the Secretary that the implementation of a new 

methodology for independent controls with subcounty controls and the 

new residence concept can wait until 2008. As we noted in our report, we 

found that controls for subcounty areas with population of more than 
Page 28 GAO-05-82 American Community Survey 

65,000 will be needed before the 2005 ACS estimates are released for these 

areas in 2006 and that controls for subcounty areas with populations of 

more than 20,000 will be needed before the first multiyear averages are 

released in 2008. (For the 2000 Census long form, controls for most areas 

of this size were from the 2000 Census short form.) With regard to the new 

residence concept, a decision to delay introducing a new methodology 

until 2008 would create time-series inconsistencies between 2000–2007 

and 2008 and subsequent years. These inconsistencies could be very 

significant for geographic areas with a large population of seasonal 

residents. 

 

The Secretary did not comment on our findings about the need for a 

methodology to revisions relating to the ICPE into the ACS. We found that 

this methodology, which is important to both the time-series consistency 

of the annual ACS estimates and to the multiyear averages, is not covered 

by the current ACS methodology, but that it will be needed when the 2010 

Decennial Census short form data become available. We found that it has 

been the Census Bureau’s practice for the ICPE, whose estimates are used 

as the independent controls for the ACS, to be benchmarked to the 

decennial census short-form data and that it uses similar practices for 

many other Census Bureau programs. For the ICPE, the Bureau will 

replace the 2010 ICPE estimates with the 2010 Census data, and use the 

differences in these estimates to revise the ICPE estimates back to the 

previous benchmark year, which for 2010 will be 2001. (Table 4 of our 

report shows the impact of benchmarking on county population data for 

2000.) It should be noted that we found that this practice is not followed in 

all Census Bureau programs. For example, for the Annual Economic and 

Social Supplement to the CPS, the Census Bureau introduced the 

benchmark information from the 2000 Decennial Census into the 2001 

estimates and presented the data on both the old and the revised basis. 

This approach, to present estimates on an old and new basis for a single 

year, may be appropriate for an annual survey. However, GAO found that 

because of the use of multiyear averages in the ACS, it is imperative that 

the ACS estimates for all years beginning with 2001 be revised. Without 

such a revision program, ACS estimates for 2010, which we assume will 

not be released until the 2010 Census short-form data have been 

incorporated, will be inconsistent with the 2009 estimates. In addition, the 

ACS estimates for 2008 and 2009 used to calculate the 5-year averages that 

will replace the 2010 Census long form will be based on controls that are 

inconsistent with those for 2010–12. Based on the revisions for 2000 shown 

in our report, there could be many significant inconsistencies, especially 

for small geographic areas. 
Page 29 GAO-05-82 American Community Survey 

Although the Secretary did not comment on the issue of revision, in its 

technical comments on our draft report, the Census Bureau reported 

(comment 22) that with regard to incorporating 2010 Census data, it has 

decided “to make appropriate changes to the [ACS] population controls 

when necessary, including the possibility of reweighting the data around 

the 2010 time period and for all multiyear estimates.” We disagree with the 

Census Bureau’s approach primarily because it is not consistent with the 

practices used by the Census Bureau to incorporate census data into 

surveys and programs such as the ICPE and monthly retail sales that are 

controlled or benchmarked to a census or similar data set. For these 

surveys, it revises all previously published data on a predetermined 

schedule using a transparent statistical procedure. Most important, these 

procedures do not depend on the size of revisions, which can only be 

determined after a benchmark is completed. Regardless of the 

benchmarking procedures adopted for the ACS, we believe that the 

Census Bureau needs to have extensive consultation with external 

stakeholders to make its decision. In addition, because of the complexity 

of most benchmarking procedures, the Census Bureau needs to begin this 

consultation as soon as possible. 

With regard to the recent Census Bureau decision about the reference 

period for the ACS, we are pleased that a decision has been made because 

any delay in this decision would have resulted in additional time-series 

inconsistencies in the ACS. We have changed our report to reflect this 

decision. Unfortunately, we have no documentation on the research 

underlying the decision and, as has been the case in other key decisions, 

we do not believe that there was any public discussion of this decision. 

The second issue identified in our report related to the operational aspects 

of the ACS, including questionnaire design and the collection of data for 

persons living in group quarters. On these issues, the Secretary limited his 

comments to the questionnaires and addressed our findings that 

improvements identified as part of the 2000 Census cognitive testing 

research and research based on comparisons of ACS and 2000 Census 

long-form data would not be completed until 2008. The Secretary noted 

that the Census Bureau has resolved the issue of finalizing the ACS 

questions, including the questions to be asked on the 2010 Census short 

form before 2008. Although this recent decision appears to have resolved 

the scheduling issue, we believe that uncertainties remain as to whether 

this schedule can be met. For example, the ACS milestones in the latest 

available schedule call for final approval of the questions by the Congress 

and by OMB in 2008 and 2009, respectively, so that any changes made as a 

result of these steps would not be incorporated into the 2008 questions. 
Page 30 GAO-05-82 American Community Survey 

As the Census Bureau has recognized, failure to maintain consistency in 

the questions for the 2008-2012 ACS will result in inconsistencies in the 5-

year averages centered on 2010, which are the averages designed to 

provide the small geographic area data that would have been collected on 

the 2010 Census long form. In addition, the recently released ACS 

evaluation reports identify issues on which new research is necessary, 

including the issues with the questions on disability identified in our 

report, but the Census Bureau has not indicated its plan to complete this 

additional research or to consult with stakeholders about decisions related 

to the research. Although the Secretary did not comment on our findings 

with regard to group quarters, we remain concerned that the work on 

group quarters being conducted as part of the 2004, 2006, and 2008 tests 

for the 2010 Census will not be reflected in the ACS beginning with 2008. 

Our report also identified as unresolved issues the two inflation 

adjustments that the Census Bureau is applying on all dollar-denominated 

ACS items. The first adjustment is used to convert annual data collected 

each month in the ACS to a calendar year basis. This adjustment 

recognizes that the annual data collected in the ACS are for different 

periods because the data are collected monthly and cover the previous 12 

months. The second adjustment is used to present dollar-denominated 

items in dollars of the most recent calendar year. This adjustment 

eliminates the impact of inflation when comparing data across years. The 

index used for both adjustments is the national-level CPI. The Secretary 

correctly observed that the CPI is a generally accepted measure of 

inflation and that most federal programs that allocate funds do not use 

regional measures of inflation. However, these observations did not 

directly address GAO’s findings about the adjustments or the concerns 

raised by HUD in its report on future use of the ACS, which are discussed 

in appendix V of our report. For example, the Secretary did not address 

our finding about a lack of a rationale for adjusting items other than 

incomes for changes in overall inflation rather than adjusting with indexes, 

such as wage rates or rent, that are directly related to the item being 

adjusted. He did indicate that the Census Bureau would reconsider its 

present policy of showing only the inflation-adjusted annual estimates and 

multiyear averages. We believe our findings about the need for the Census 

Bureau to provide a comprehensive rationale for the two adjustments still 

apply. 

The Secretary disagreed with the issue we identified on completeness of 

the Census Bureau’s comparison and evaluation reports. He noted that 

after our draft report was completed, the Census Bureau released seven 

additional comparison reports and that it planned to prepare additional 
Page 31 GAO-05-82 American Community Survey 

reports to evaluate issues we identified on the time-series consistency of 

the annual ACS estimates. However, despite earlier statements by the 

Census Bureau to compare and evaluate differences between state-level 

estimates from the Census 2000 Supplementary Survey (C2SS) and the 

2000 Census long form, these reports did not include any reference to the 

preparation of such comparisons, and the Secretary did not indicate they 

would be prepared. Because the focus of the long form and the ACS is on 

data from small geographic areas, we believe that reports on states and on 

other areas with population of 250,000 or more should be prepared. 

The last issue we identified was the need to provide users with guidance 

on the interpretation of key properties of multiyear averages. The 

Secretary agreed about the need but noted that guidance is not needed in 

2005. He reported on a newly created NAS panel that will be studying 

many of the key issues identified in our report. However, we believe that 

the Census Bureau should begin to release guidance on the averages 

before the first multiyear averages are released in 2008. One area in which 

such guidance will be needed is the interpretation and use of the multiple 

ACS estimates. When the 2005–07 averages are released in 2008, users will 

have annual estimates for some of these areas for 2006 as well as the 3-

year averages, which will be centered on 2006. In 2010, when the first 5-

year averages are released (2005–09), users will have three sets of ACS 

estimates for places with populations larger than 20,000. For example, for 

each state, there will be an annual estimate for 2007 as well as 3-year and 

5-year averages centered on 2007. 

The comments from the Secretary also include a list of detailed technical 

comments from the Census Bureau. We reviewed each of these comments 

and revised the report where appropriate. 

As agreed with your offices, unless you release the report’s contents 

earlier, we plan no further distribution of it until 30 days from its issue 

date. We will then send copies to the Secretary of Commerce, the Director 

of the U.S. Census Bureau, and others who are interested. Copies will be 

made available to others on request. This report will also be available at no 

charge on GAO’s Web site at http://www.gao.gov. 
Page 32 GAO-05-82 American Community Survey 

If you or your staff have any questions concerning this report, please 

contact me at (202) 512-9750. Other staff who made major contributions to 

this report are listed in appendix VII. 

Robert P. Parker 

Chief Statistician 
Appendix I: Scope and Methodology 

Page 33 GAO-05-82 American Community Survey 

We used a combination of approaches and methods to examine the Census 

Bureau’s plans to develop, test, and implement the American Community 

Survey (ACS). We reviewed published and unpublished ACS-related 

Census Bureau reports, papers, presentations, budget documents, and 

congressional testimony; National Academy of Sciences (NAS) reports; 

congressional testimony delivered by outside experts; and consultants’ 

reports prepared for the Census Bureau, the Bureau of Labor Statistics 

(BLS), and the Department of Housing and Urban Development (HUD). 

We reviewed an extensive set of internal planning documents prepared 

between 1992 and 1995 that the Census Bureau provided, relevant papers 

Census Bureau staff presented at professional association meetings and 

similar symposiums from 1995 on, and evaluation reports based on the 

2000 Census. We also reviewed official Census Bureau presentations in 

special reports, congressional testimony, and recent advisory committee 

meetings. We reviewed similar materials NAS and consultants prepared for 

the Census Bureau and other federal agencies, as well as materials we 

prepared. The most important documents we reviewed are listed in the 

bibliography, organized by document type, at the end of this report. 

In addition, we conducted independent research and analysis. To assess 

the evaluations the Census Bureau conducted to assist users in making the 

transition from the 2000 Census long form to the ACS, we obtained data 

from the 2000 Census and 2000 ACS (the Census 2000 Supplementary 

Survey) and prepared comparisons of key detailed data items at the state 

level. To determine the potential effect of replacing independent 

population and housing characteristics controls from the 2000 Census with 

corresponding data from the 2010 Census, we compared county-level 

intercensal estimates for April 1, 2000, based on the 1990 Census, with 

2000 Census counts. We also analyzed the Census Bureau’s use of 

independent controls for estimates of population and housing 

characteristics for previous decennial censuses and its plans for the ACS. 

To assess alternatives to the ACS, we spoke to current Census Bureau 

officials and individuals familiar with early efforts to provide more 

frequent long-form type data, including the Mid-Decade Census. We also 

reviewed congressional hearings on these developments and Census 

Bureau documents prepared in the 1990s on the Continuous Measurement 

program and on implementing the ACS to replace the 2000 Census long 

form. We did not independently verify the cost information the Census 

Bureau provided for the alternative we discuss. We also interviewed staff 

of the NAS Committee on National Statistics and outside small-area data 

experts. The outside experts we interviewed were 

Appendix I: Scope and Methodology 
Appendix I: Scope and Methodology 

Page 34 GAO-05-82 American Community Survey 

Constance Citro, Committee on National Statistics 

Michael Cohen, Committee on National Statistics 

Linda Gage, California State Department of Finance 

Edwin Goldfield, Committee on National Statistics 

Ken Hodges, Claritas Inc. 

Graham Kalton, Westat Inc. 

Terri Ann Lowenthal, Consultant 

Joseph Salvo, New York City Planning Department 

Edward J. Spar, Council of Professional Associations for Federal Statistics 

Paul Voss, University of Wisconsin 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 35 GAO-05-82 American Community Survey 

In Modernizing the U.S. Census, a 1995 report, the NAS Panel on Census 

Requirements in the Year 2000 and Beyond stated that 

“Although we believe that the proposed continuous measurement system deserves serious 

evaluation, we conclude that much work remains to develop credible estimates of its net 

costs and to answer many other fundamental questions about data quality, the use of smallarea estimates based on cumulated data, how continuous measurement could be integrated 

with existing household surveys, and its advantages compared with other means of 

providing more frequent small-area estimates. In our judgment, it will not be possible to 

complete this work in time to consider the use of continuous measurement in place of the 

long form for the 2000 census.”1

The panel concluded that 

“With regard to proposals to drop the long form in the next decennial census and substitute 

a continuous monthly survey to obtain relevant data, substantial further research and 

preparatory work are required to thoroughly evaluate the likely effect and costs of these 

proposals. Continuous measurement deserves serious consideration as a means of 

providing more frequent small-area data; however, the necessary research and evaluation 

cannot be completed in time for the 2000 census.” 2

Although 1994 saw the first proposals to implement the continuous 

measurement methodology as a replacement for the 2000 Census long 

form, the Census Bureau changed its plans in 1998, shifting to 

implementation to replace the long form in 2010. 

Since 1995, NAS has produced several reports that relate totally or in part 

to the ACS, including a summary of a September 13, 1998, Committee on 

National Statistics workshop at NAS, two interim reports, a letter report, 

and a final report, by the Panel on Research on Future Census Methods, 

and a report released in early 2004 by the Panel to Review the 2000 

 1

See Barry Edmonston and Charles Schultze, eds., Modernizing the U.S. Census 

(Washington, D.C.: National Academies Press, 1995), p. 9. The panel was mandated by 

Public Law 102-125 and funded by the Census Bureau. 

2

Edmonston and Schultze, p. 3. 

Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 36 GAO-05-82 American Community Survey 

Census.3 (In this appendix, we do not discuss NAS reports after 1995 in 

which the ACS was discussed as a potential data source for federal 

programs.4

) 

With few exceptions, the members of these two NAS panels and the 

workshop participants reported findings that cover most of what we have 

identified as unresolved issues and summarize in this appendix.5

 The NAS 

reports and ours differ somewhat in emphasis. We have focused on the 

production and use of ACS data, whereas NAS focused more on data 

collection and processing methodologies. These differences may reflect 

the fact that NAS panel members are very sophisticated users who are 

more likely to use ACS microdata files and make their own adjustments 

for methodological issues; they make little use of the regular ACS 

publications. 

NAS sponsored a 1-day workshop in September 1998 to discuss 

methodological issues related to the ACS. Experts prepared “thought 

pieces” on issues NAS staff selected, with input from Census Bureau staff. 

The workshop’s specific discussion topics were combinations of 

information across areas and across time, funding formula, weighting and 

imputation, sample and questionnaire design, and calibration of the output 

from this survey with that from the long form. The thought pieces and 

 3

See National Research Council, Committee on National Statistics, The American 

Community Survey: Summary of a Workshop (Washington, D.C.: National Academy 

Press, 2001); Michael L. Cohen and Benjamin F. King, eds., Designing the 2010 Census: 

First Interim Report (Washington, D.C.: National Academy Press, 2000); Benjamin F. King, 

National Academy of Sciences, to William Barron, U.S. Bureau of the Census, February 15, 

2001; Daniel L. Cork, Michael L. Cohen, and Benjamin F. King, eds., Planning the 2010 

Census: Second Interim Report (Washington, D.C.: National Academies Press, 2003); 

Daniel L. Cork, Michael L. Cohen, and Benjamin F. King, eds., Reengineering the 2010 

Census: Risks and Challenges (Washington, D.C.: National Academies Press, 2004); and 

Constance F. Citro, Daniel L. Cork, and Janet L. Norwood, eds., The 2000 Census: 

Counting under Adversity (Washington, D.C.: National Academies Press, 2004). 

4

See, for example, Constance F. Citro and Graham Kalton, eds., Small-Area Income and 

Poverty Estimates: Priorities for 2000 and Beyond (Washington, D.C.: National Academy 

Press, 2000), and Thomas B. Jabine, Thomas A. Louis, and Allen L. Schirm, eds., Choosing 

the Right Formula: Initial Report (Washington, D.C.: National Academy Press, 2001). 

5

The exceptions are the Census Bureau’s inflation adjustments for dollar-denominated data 

items and the specific use of 2010 Census population and housing controls. 

1998 NAS Workshop 

on the ACS 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 37 GAO-05-82 American Community Survey 

comments on them prepared Census Bureau staff for the discussions at 

the workshop.6

NAS noted in the report on the conference that its six focus issues 

reflected only a partial list of key ACS topics; the report’s conclusions 

identified other key issues.7

 Stating that the workshop’s purpose was “to 

assist the Census Bureau in developing a research agenda to address these 

and other methodological issues,” the report pointed out that the Census 

Bureau’s past focus on the ACS 

“has been on refining data collection, leaving the final answers to the difficult analysis 

questions for later. Thus, procedures for nonresponse and undercoverage adjustment were 

modeled, to the extent possible, after current procedures used for the census long form. 

Now that data collection has matured as the ACS demonstration phase is well under way, 

the Census Bureau is developing a research plan and initiating research to address all 

issues relating to ACS methodology. Fall 1998 therefore seemed an opportune moment for 

a workshop to assist the Census Bureau in developing a research agenda to deal with many 

of these challenging issues.” 8

The report contained no specific recommendations but identified areas 

where additional research was needed, including issues we have 

expressed concern about, such as the availability of multiple ACS 

estimates for geographic areas with populations larger than 20,000 and the 

likelihood of differences between ACS estimates and estimates from a 

Decennial Census short form. From our perspective, the most relevant of 

the workshop’s specific issues were (1) combining information across 

time, (2) weighting and imputation, and (3) calibrating the output from this 

survey with that from the long form. 

Technical papers in the workshop’s agenda book contained considerable 

discussion of time-series issues. The discussion in this section of the 

workshop focused on replacing moving averages with time-series 

modeling and using current household survey data to develop models. 

Speaking for the Census Bureau, Alexander stated that “Our current plan 

 6

Charles Alexander, of the Census Bureau’s Demographic Statistical Methods Division, who 

had directed most of its research on the ACS, prepared comments for the Census Bureau. 

See National Research Council, Committee on National Statistics, The American 

Community Survey: Summary of a Workshop, p. 5. 

7

National Research Council, pp. 48–49. 

8

National Research Council, pp. 1 and 3. 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 38 GAO-05-82 American Community Survey 

is to release annual data for even very small areas and let users perform 

their own time series analyses. We welcome ideas about what the Bureau’s 

role should be . . .”9

On the evaluation of comparisons between the ACS test data, the 

workshop report noted that the objective of the comparison using the 

national sample data was 

“to make comparisons between the long form and ACS for all states, large metropolitan 

areas, large substate areas, and population groups. 

“The objective of the 1999–2001 comparison is to understand the factors associated with 

the differences between the 1999–2001 ACS and the 2000 long form in the 31 areas, using 

the second comparison study to develop a calibration model to adjust the 2000 long-form 

estimates to roughly represent what the full ACS would have yielded in 2000.”10

Chapter 7 of the report was devoted to a discussion of calibration. The 

report stated that the model would “determine the effects that would be 

expected when switching from the long-form estimates to those from the 

ACS on various applications of long-form data.” Once adjusted, the 

calibrated long-form data for 2000 can be compared with ACS data that are 

collected following full field implementation in 2003, “in order to 

understand the dynamics over time of such characteristics as poverty and 

employment.”11

The technical papers in the workshop’s agenda book also noted other 

comparisons of ACS data. For example, Alexander discussed comparisons 

with CPS data, reporting that 

“We very much like the idea of viewing information from an ongoing comparison of ACS to 

CPS and other surveys as a way to help understand how the ACS ‘error profile’ might be 

 9

Charles Alexander, Technical Paper, prepared for Workshop on the American Community 

Survey, Committee on National Statistics, National Academy of Sciences, Washington, D.C., 

September 1998, p. 3-2. 

10National Research Council, p. 4. 

11National Research Council, pp. 4 and 5. The Census Bureau provided funding for the 

development of this model in fiscal year 1999, but there is no report that the model was 

completed. 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 39 GAO-05-82 American Community Survey 

changing over time and using this to help interpret ACS data in the context of the long-term 

time series of census estimates.”12

The use of independent controls for population and housing 

characteristics was also discussed at the workshop, but very generally, 

because the Census Bureau had not yet developed proposals for the 

controls. For example, the report’s chapter 5 discussed improving the 

existing population controls. The Census Bureau reported discomfort with 

the quality of the existing county-level controls (from ICPE) and agreed 

that the ACS could be used to improve these estimates.13 The Census 

Bureau also acknowledged that differences in residence rules and 

reference period would complicate the calculation of population weights. 

However, no discussion was reported of how the population counts from 

the 2010 Census would be used. 

The report referred to moving averages in the conclusions chapter as one 

of the methodological problems noted at the workshop: 

“the development of estimates that (a) sum to estimates at higher levels of geographic 

aggregation and (b) more closely approximate direct estimates at higher levels of 

aggregation . . . in the event that aggregate estimates are not constrained to 

(approximately) equal direct estimates (and also the release of direct estimates at lower 

levels of aggregation for analysis purposes) . . . .”14

The Panel on Research on Future Census Methods, sponsored by the 

Census Bureau, was formed to examine alternative designs for the 

2010 Census and to assist the Census Bureau in planning tests and 

analyses to help assess and compare their advantages and disadvantages. 

In addition to the first interim report, Designing the 2010 Census, 

released in 2000, a letter report was issued in 2001, and a second interim 

report was issued in 2003 (both discussed below). The panel issued a final 

report in 2004. 

The panel’s first interim report identified information from 2000 Census 

data useful in assessing designs for the 2010 Census. In the executive 

 12Alexander, Technical Paper, pp. 3–7. 

13National Research Council, p. 26. 

14National Research Council, p. 48. 

2000 Interim Report 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 40 GAO-05-82 American Community Survey 

summary, the panel made four specific recommendations and proposed 

other changes. One of the recommendations, relating to evaluation studies, 

is directly relevant to our report: 

“The Census Bureau should develop a detailed plan for each evaluation study on how to 

analyze the data collected and how to use the results in decision making concerning 2010 

census design. The Census Bureau should then use these plans to identify the benefits and 

resources required for each evaluation study, set priorities among them, and allocate 

sufficient resources for the careful completion of all or, at least, the highest priority 

evaluations.”15

In addition, the report proposed three changes for the 2010 Census and 

ACS. The first proposed change to the direction and nature of the 

evaluation program, was that the Census Bureau use the “ACS as a census 

testing platform”: 

“The American Community Survey is a proposed national, continuous, mailout-mailback 

survey of 250,000 households per month, with field follow-up that makes use of techniques 

closely related to those used in the census. Therefore, rather than rely exclusively on the 

two or three large-scale census tests, which are always at least slightly limited in their 

generalizability by the specific locations selected, the Census Bureau could use the ACS as 

a platform for testing possible changes in the census. This work could serve as preliminary 

testing to the larger mid-decade tests for the census design.”16

The second proposed change called for “a match study of the census short 

form and the ACS.” This proposal, which could provide information on the 

effect of a change in the residence rule in the 2010 census, stated: 

“The decennial census makes use of one residence rule definition, the ACS uses a second, 

and a third approach is being tested in the alternative questionnaire study. As the Census 

Bureau is well aware (based on the allocation of an experiment to this issue), confusion 

over residence rules is a source of possibly substantial error in the census. . . . The Census 

Bureau needs to find the residence rule (within the set of rules satisfying legal and other 

restrictions) that results in the most accurate estimates. To learn more about this issue, the 

 15Michael L. Cohen and Benjamin F. King, eds., Designing the 2010 Census: First Interim 

Report (Washington, D.C.: National Academy Press, 2000), p. 2. The three other 

recommendations covered the master trace sample database, the 2000 Census 

administrative records research program, and the activities of local organizations that 

helped with the census count. 

16Cohen and King, p. 34. 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 41 GAO-05-82 American Community Survey 

panel proposes an ACS-short-form match study in 2000 to examine this and other shortform measurement error issues.”17

The third proposed change was the recommendation that the Census 

Bureau “form an ACS advisory group” to improve its efforts to consult 

with stakeholders. The panel stated: 

“The development of the ACS raises a number of issues related to the quality of and 

planning for the 2010 census. There are also many other important technical issues raised 

by the introduction of the ACS into the federal statistical system. Formation of a technical 

working group could help to address many of these issues.”18

The 2001 letter report—addressed from Benjamin King, Chair of the Panel 

on Research on Future Census Methods, to William Barron Jr., Acting 

Director of the Census Bureau—was prepared in response to a December 

7, 2000, presentation by Census Bureau staff on the major elements of the 

Census Bureau’s strategy for the 2010 Census. The panel recommended 

that the Census Bureau produce a “business plan” for the 2010 Census that 

would provide an overall framework for development. It recommended 

that this plan include (1) a statement of objectives, (2) a timeline for 

completing tasks, (3) a cost-benefit analysis, and (4) more complete 

information on coordinating tasks within the Census Bureau.19 The panel 

also recommended the preparation of specific types of evaluation studies. 

On the evaluation studies, the panel reported, 

“The Bureau is currently conducting a wide array of evaluation studies and experiments 

designed to assess the quality of the 2000 census and inform approaches to the 2010 

census. As noted above, the panel applauds the scope of these evaluation studies. However, 

the panel is concerned that the Bureau has not sufficiently focused its evaluation program 

and has instead labeled most of its evaluation categories as high priority.”20

 17Cohen and King, pp. 34–35. 

18Cohen and King, eds., p. 38. The Census Bureau has established the Federal Agency 

Information Program on the ACS in response to a recommendation we made in 

GAO-02-956R, p. 25. Information is at the Census Bureau’s Web site at 

http://www.census.gov/acs/www/. 

19These recommendations were similar to recommendations we made in GAO-04-37, pp. 

33–34. 

20King, to Barron, p. 3. 

2001 Letter Report 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 42 GAO-05-82 American Community Survey 

In the letter report’s conclusions, the panel recommended that the Census 

Bureau give the highest priority to studies and data analysis in seven 

specific areas, most of which related to the ACS. The panel’s list of studies 

and analyses included the following recommendations, which we have 

also discussed: 

“comparison of estimates from the ACS and 2000 census long-form data, in sites where 

both are available; coverage of the population, disaggregated by demographic and 

geographic subgroups; the effectiveness of major automated systems for data collection, 

capture, and processing; the quality and completeness of long-form data collection; and the 

effectiveness of operations used to designate special places and enumerate the group 

quarters and homeless populations.”21

In making these recommendations, the panel noted the need for the 

Census Bureau to maintain a strategy that would provide for “a smooth 

transition” from the long form to the ACS. The panel urged the Census 

Bureau 

“to broaden its justification for the ACS, detailing the need for and use of long-form data 

and how those data needs will be addressed through the ACS, perhaps in conjunction with 

the CPS and other demographic surveys. Accordingly, the Bureau should expedite ongoing 

evaluations that assess the quality of ACS data relative to the quality associated with the 

traditional census long form.”22

In the second interim report, Planning the 2010 Census, issued in 2003, the 

panel identified four areas of primary interest: reengineering the census, 

geographic coding, the ACS, and testing for the 2010 Census. With regard 

to the ACS, the panel reported in the executive summary that 

“The most basic question the panel faces regarding the ACS is whether it is a satisfactory 

replacement for the census long form. We recognize that significant estimation and 

weighting challenges must be addressed and that more research is needed on the relative 

quality of ACS and long-form estimates.”23

 21King, to Barron, p. 4. The other studies related to the 2000 Census mailing list and the 

effect of local partnerships on the 2000 Census collection process. 

22King, to Barron, p. 2. 

23Cork, Cohen, and King, p. 6. 

2003 Interim Report 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 43 GAO-05-82 American Community Survey 

The panel found that the Census Bureau needed to complete evaluations 

of differences between 2000 Census long-form data and data from the ACS 

test sites and from the 2000–02 supplementary surveys. It also found that 

the Census Bureau needed to undertake a major effort to inform data 

users and stakeholders of the results of these evaluations and the features 

and problems of working with multiyear averages. One of the four main 

topics of this report was a separate chapter on the ACS, in which the panel 

discussed the following recommendations: 

“The Census Bureau should carry out more research to understand the differences between 

and relative quality of ACS estimates and long-form estimates, with particular attention to 

measurement error and error from nonresponse and imputation. The Census Bureau must 

work on ways to effectively communicate and articulate those findings to interested 

stakeholders, particularly potential end users of the data. 

The Census Bureau should make ACS data available (protecting confidentiality) to analysts 

in the 31 ACS test sites to facilitate the comparison of ACS and census long-form estimates 

as a means of assessing the quality of ACS data as a replacement for census long-form data. 

Again, with appropriate safeguards, the Census Bureau should release ACS data to the 

broader research community for evaluation purposes. 

The Census Bureau should issue a user’s guide that details the statistical implications of 

the difference between point-in-time and moving average estimates for various uses. 

The Census Bureau should identify the costs and benefits of various approaches to 

collecting characteristics information should support for the full ACS not be forthcoming. 

These costs and benefits should be presented for review so that decisions on the ACS and 

its alternatives can be fully informed.”24

With regard to the first recommendation, the panel stated that 

“The fact that the Census Bureau has not done more in comparing the data collected from 

the 31 test sites, the C2SS, and the 2001 and 2002 Supplementary Surveys with the data 

collected by the 2000 census long form is disappointing. Such analyses would help assess 

the quality of ACS data and would be helpful in making the argument for transition from 

the long form to the ACS. This deficiency is probably due to limited analytic resources at 

 24Cork, Cohen, and King, pp. 99–102. As we noted above, we discussed issues related to 

planning for the 2010 Census in GAO-04-37. 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 44 GAO-05-82 American Community Survey 

the Census Bureau and creates an argument for ‘farming out’ this analysis to outside 

researchers.”25

On the recommendation about the need for more information on multiyear 

or moving averages, the panel discussed several technical issues. The 

panel commented that 

“The ramifications of this basic concept emerge when moving average estimates are 

entered into sensitive allocation formulas or compared against strict eligibility cutoffs. A 

smoothed estimate may mask or smooth over an individual year drop in level of need, thus 

keeping the locality eligible for benefits; conversely, it may also mask individual-year 

spikes in activity and thus disqualify an area from benefits. It is clear that the use of 

smoothed estimates is neither uniformly advantageous nor disadvantageous to a locality; 

what is not clear is how often major discrepancies may occur in practice.”26

On using moving-average data to measure year-to-year changes, the panel 

commented: 

“It is incorrect to use annual estimates based on moving averages over several years when 

assessing change since some of the data are from overlapping time periods and hence 

identical. At the least, the results will yield incorrect estimates of the variance of the 

estimates of change. Therefore, users should be cautioned about this aspect of the use of 

moving averages.”27

In both recommendations on evaluations and moving averages, the panel 

called for the Census Bureau to engage in a greatly expanded effort to 

inform users and stakeholders. It also suggested that the Census Bureau 

farm out some of the research efforts. 

In summarizing the results of its efforts, the panel noted the 1995 NAS 

report, as follows: 

“Eight years later, faced with the task of offering advice on making the vision of continuous 

measurement a reality in the 2010 census, the similarity between the arguments then and 

now is uncanny. Similar, too, are the points of concern; the current panel is hard-pressed to 

improve upon the basic summary of concerns outlined by our predecessors. We are, 

 25Cork, Cohen, and King, p. 99. 

26Cork, Cohen, and King, p. 86. 

27Cork, Cohen, and King, p. 87. 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 45 GAO-05-82 American Community Survey 

however, much more sanguine that a compelling case can be made for the ACS and that it 

is a viable long-form replacement in the 2010 census.”28

However, while the panel was identifying its concerns, it also supported 

full funding of the ACS, believing that existing “flaws” in the plan could be 

resolved. 

In 2004, the Panel to Review the 2000 Census, sponsored by the Census 

Bureau, issued a report entitled The 2000 Census: Counting under 

Adversity. The findings were based primarily on the panel’s review of 

information from the 2000 Census. The panel’s charge had been to “review 

the statistical methods of the 2000 Census, particularly the use of the 

Accuracy and Coverage Evaluation Program and dual-systems estimation, 

and other census procedures that may affect the completeness and quality 

of the data.”29 Thus, although the report focused on the 2000 Census, it 

made some recommendations for improving the 2010 Census. Its major 

recommendation was that 

“the Census Bureau, the administration, and Congress agree on the basic design for the 

2010 census no later than 2006 in order to permit an appropriate, well-planned dress 

rehearsal in 2008. In particular, this agreement should specify the role of the new American 

Community Survey (ACS). Further delay will undercut the ability of the ACS to provide, by 

2010, small-area data of the type traditionally collected on the census long-form sample and 

will jeopardize 2010 planning, which currently assumes a short-form-only census.”30

In its discussion of the 2010 Census, the report included several 

recommendations on ACS operations and evaluations. The panel 

recommended that the Census Bureau develop estimates of the effect on 

estimates from the 2000 long form resulting from imputation as well as 

sampling variability and nonresponse. More specifically, 

“the Bureau should also study the effects of imputation on the distributions of 

characteristics and the relationships among them and conduct research on improved 

 28Cork, Cohen, and King, p. 98. 

29Citro, Cork, and Norwood, eds., The 2000 Census: Counting under Adversity, p. 1. 

30Citro, Cork, and Norwood, pp. 2–3. 

The 2000 Census: 

Counting under 

Adversity 
Appendix II: Recent NAS Findings on 

Continuous Measurement and the ACS 

Page 46 GAO-05-82 American Community Survey 

imputation methods for use in the American Community Survey (or the 2010 census if it 

includes a long-form sample).”31

Finally, the panel recommended that the Census Bureau’s plans for the 

2010 Census “include research on the trade-offs in costs and accuracy 

between imputation and additional fieldwork for missing data 

(Recommendation 4.2).”32 The panel also recommended that the Census 

Bureau 

“publish distributions of characteristics and item imputation rates, for the 2010 census and 

the American Community Survey (when it includes group quarters residents), that 

distinguish household residents from the group quarters population (at least the 

institutionalized component). Such separation would make it easier for data users to 

compare census and ACS estimates with household surveys and would facilitate 

comparative assessments of data quality for these two populations by the Census Bureau 

and others.”33

The panel’s findings were similar to our findings, with one major 

difference. The panel’s findings imply that some research on the ACS can 

be conducted after the results of the 2010 Census short form become 

available. In contrast, we see that such research is needed in order to 

improve the ACS by 2008, the first year in which ACS data will enter into 

the calculation of the 5-year average estimates (2008–12) that will replace 

the long form. 

 31Citro, Cork, and Norwood, pp. 10–11. 

32Citro, Cork, and Norwood, p. 11. 

33Citro, Cork, and Norwood, p. 301. See recommendations 7.1 and 7.3. 
Appendix III: The Decennial Census Long 

Form and the Evolution of the ACS Plan 

Page 47 GAO-05-82 American Community Survey 

In the decennial census for 1940 and for 1950, the Census Bureau used a 

single form to collect, from all households, population and key 

characteristics such as age and gender and, from a sample of households, 

detailed demographic, economic, and housing items. In the 1940 Census, 

the Census Bureau used a sample of 5 percent of the population to collect 

data on questions on income, internal migration, and Social Security 

status, as well as on more refined questions on unemployment. In addition, 

the Congress authorized a new set of questions about the types of 

plumbing, heating, and appliances in dwellings. 

Beginning with the 1960 Census, the first conducted by mail, it became 

necessary to use separate forms—a short form to collect population data 

from all households and a long form to collect the detailed items from a 

sample of households. In the 2000 Census, for example, the Census Bureau 

conducted a sample of 17 percent of the population and asked 

45 questions on the long form. Since 1960, the long form has evolved into a 

cost-efficient way to collect data federal agencies need that minimizes 

respondent burden. For 2000, for example, the long form consisted of 

45 questions that the Census Bureau developed working through OMB and 

with the consent of the Congress.1

 Each question provided information 

required by statute. Thus, the 2000 long form provided all federal 

departments and agencies with critical data, and it was estimated that 

these data were used to allocate more than $200 billion in federal funds.2

In the 1950s, Census Bureau officials and users of Decennial Census data 

had begun to develop a program to provide intercensal data on population 

characteristics. The first major proposal to provide intercensal data called 

for a mid-decade census that would provide information every 5 years. In 

1976, the Congress enacted legislation to require a mid-decade census 

beginning with 1985, but did not fully fund the program. 

In the late 1980s, the Census Bureau shifted efforts to provide intercensal 

estimates to a program based on CM methodology, or Continuous 

 1

The long form is also discussed in Joseph Salvo and Arun Peter Lobo, “The American 

Community Survey: Quality of Response by Mode of Data Collection in the Bronx Test 

Site,” presented at 2002 Joint Statistical Meetings, New York, August 14, 2002; Margo 

Anderson, ed., Encyclopedia of the U.S. Census (Washington, D.C.: CQ Press, 2000); and 

GAO, Decennial Census: Overview of Historical Census Issues, GAO/GGD-98-103

(Washington, D.C.: May 1, 1998). 

2

See GAO-02-956R. 

Appendix III: The Decennial Census Long 

Form and the Evolution of the ACS Plan 

Decennial Census 

Long Form 

Evolution of ACS Plan 
Appendix III: The Decennial Census Long 

Form and the Evolution of the ACS Plan 

Page 48 GAO-05-82 American Community Survey 

Measurement. This approach would provide for more timely population 

data as well as the detailed demographic, economic, and housing data 

collected every 10 years by the Decennial Census long form.3

 The program 

would integrate a new sample survey, existing surveys, administrative 

records, and statistical modeling. After a thorough analysis of alternatives 

based on this methodology, the Census Bureau developed a plan similar to 

the current ACS to replace the 2000 Census long form. 

Initial $2.6 million funding for the CM program was included in the 

2000 Decennial Census budget for fiscal year 1995. These funds were to 

develop, test, and evaluate a CM program to replace the Decennial Census 

long form and to provide more timely long-form type data. In the program 

description in the budget documents, the Census Bureau reported that it 

planned to develop the new program that would integrate a new sample 

survey, existing surveys, administrative records, and statistical modeling. 

Table 2 shows that about $330 million has been provided to fund the CM 

program since 1995, with funding provided separately until 2003 and 

additional funding from both the 2000 and 2010 Decennial Census 

programs. Beginning with 2003, all funding has been provided as part of 

the 2010 Census program. The Census Bureau requested 

$165 million for fiscal year 2005. 

 3

Data items similar or identical to those collected on the long form are collected by the 

Annual Demographic Survey (CPS’s March supplement), Annual Housing Survey, and other 

surveys. However, these surveys’ samples limit the data they provide to the national level 

and selected states and metropolitan areas. Annual data for all small geographic areas are 

available from (1) administrative records on unemployment insurance and wages and 

federal income tax and Medicare records; (2) statistical series the Bureau of Economic 

Analysis (BEA) prepares, such as local area personal income data; and (3) model-based 

series such as the Census Bureau’s Small Area Income and Poverty Estimates program. 
Appendix III: The Decennial Census Long 

Form and the Evolution of the ACS Plan 

Page 49 GAO-05-82 American Community Survey 

Table 2: Continuous Measurement and ACS Funding, Fiscal Years 1995–2005 

Fiscal year Budgeta Activity Other information 

1995 $2.6 Develop and test a continuous measurement (CM) system to 

replace 2000 Census long form; study integration of 

administrative records, existing current surveys, and statistical 

modeling with a new survey for CM programs 

None 

1996 10.0 Develop and test a CM system to replace 2000 Census long 

form and provide annual data 

Continue evaluating and developing an 

integrated CM program 

1997 16.6 Rename test survey American Community Survey (ACS); 

complete data collection and processing for 1996 survey at 

4 test sites; develop list to cover group quarters 

Develop methods for integrating 

administrative records and information from 

household survey data into CM program 

1998 16.6 Continue testing and processing 1997 test site survey data Make long-run plans for replacing 2010 long 

form with full implementation of ACS in 

2003 

1999 20.0 Publish 1998 test site data and expand test site surveys to 

31 sites; prepare for supplementary surveys from national 

sample to begin with 2000 to compare with 2000 Census longform data 

Develop statistical models to evaluate 

comparisons of long form to supplementary 

surveys; continue testing to integrate 

information from administrative records 

2000 47.0 Provide for 2000 supplementary survey; continue comparison 

studies of differences for test site areas; develop plans for 

comparison studies with supplementary survey and using 

multiyear averages 

None 

2001 45.2 Provide for continuation of supplementary surveys; continue 

testing and comparison studies with data from test sites and 

national survey; begin testing in Puerto Rico 

Continue processing data from test sites for 

comparison studies 

2002 56.1 Prepare for full implementation in 2003 Continue evaluating comparison studies for 

test-site and supplementary survey data 

2003 57.1 Prepare to begin full implementation for 2005 Complete testing for group quarters and 

Puerto Rico 

2004 64.8 Prepare to begin full implementation for 2005 None 

2005 165.0 Full implementation None 

Sources: Budget of the United States, House of Representatives Report 108-401, and Census Bureau budget documents. 

a

Dollars in millions. Fiscal year 1995 funding provided as part of the 2000 Decennial Census program. 

Fiscal year 1996–99 funding provided by CM program. Fiscal year 2000 and 2001 funding provided 

as both the CM program and part of the 2000 Census program. Fiscal year 2002 funding provided as 

both the CM program and part of the 2010 Census program. Beginning with fiscal year 2003, funding 

provided as part of the 2010 Census program. Fiscal year 2005 figure is the budget request. 

In 1996 and 1997, funding was provided to field-test what became the ACS, 

to replace the 2000 Census long form. The ACS was to begin in 1999 with 

an annual sample of 4.8 million housing units for 1999, 2000, and 2001 and 

3 million housing units for subsequent years. Under this plan, a 3-year 
Appendix III: The Decennial Census Long 

Form and the Evolution of the ACS Plan 

Page 50 GAO-05-82 American Community Survey 

average of ACS data for 1999–2001 was to replace the 2000 Census long 

form.4

 It would provide the same detailed items and same level of 

geographic detail as the traditional long form with about the same quality. 

Annual ACS data would subsequently be provided for geographic areas 

with populations of 65,000 or more, 3-year averages would provide ACS 

data for geographic areas with populations larger than 20,000, and 5-year 

averages would provide ACS data for small geographic areas, such as 

census tracts, small towns, and rural areas. The 5-year average for 

2010, 2020, and beyond would replace future Decennial Census long forms. 

In the 1998 budget request, the Census Bureau shifted the timing for 

replacing the long form from the 2000 Census to the 2010 Census. As a 

result, it was funded to conduct annual supplementary surveys of 

750,000 households beginning with 2000, in addition to the ACS testing at 

four test sites (or counties). The Census 2000 Supplementary Survey, 

known as C2SS, and the surveys for subsequent years were to be used to 

test the feasibility of collecting long-form data at the same time as, but in a 

separate process from, the Decennial Census. Data from C2SS and the 

supplementary surveys were also to be used to test ACS data usability and 

reliability and to evaluate operational and programmatic issues associated 

with implementing the ACS. Also, the number of test sites was increased 

to 31 by 1999. Funding to compare and evaluate differences between data 

collected from the 2000 Census long form and the ACS testing programs 

began in 1999, to develop data to expand coverage to group quarters and 

Puerto Rico in 2001. Plans to integrate existing surveys, administrative 

records, and statistical modeling into the new program were dropped in 

2001. 

The 1998 budget request also reported that the Census Bureau would 

proceed with plans to replace the 2010 Census long form with an ACS 

based on an annual sample of 3 million housing units, as with the previous 

plan. Unlike that plan, the sample size for 2009–11 would not increase to 

provide 3-year averages for 2010. This revised plan called for full 

implementation of the ACS in 2003. Full ACS data for 2003 to 2007 would 

have made 5-year averages available in 2008, 4 years before the long-form 

sample statistics from the 2010 Census would become available. However, 

 4

Harry A. Scarr presented this proposal as Deputy Director of the Census Bureau at an 

Association of Public Data Users conference in Fredericksburg, Virginia, on October 16, 

1994. 
Appendix III: The Decennial Census Long 

Form and the Evolution of the ACS Plan 

Page 51 GAO-05-82 American Community Survey 

budget decisions by the Congress delayed full implementation until the 

fourth quarter of fiscal year 2004. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 52 GAO-05-82 American Community Survey 

The Congress initially provided funds for testing the CM methodology in 

1994. As we have noted, the Census Bureau had begun formal testing of 

the CM program in 1996 with an operational test of the ACS in four 

counties; this test was expanded to 31 test sites by 1999. A second testing 

program, the Supplementary Survey program, began in 2000 as a part of 

the 2000 Decennial Census. The Census Bureau designed C2SS to test the 

feasibility of collecting long-form data at the same time as, but in a 

separate process from, the 2000 Decennial Census. Data from C2SS and 

the same supplementary surveys, beginning with 2001, were also to be 

used to test ACS data usability and reliability. According to the Census 

Bureau, these surveys were to be used to examine technical, statistical, 

and operational issues associated with implementing the ACS and to 

document the key results in a series of reports.1

Before field testing began, the Census Bureau had conducted an extensive 

research program to identify the issues related to using the CM 

methodology and to replacing the long form. The research program 

resulted in a series of 20 reports, known as the Continuous Measurement 

Series, between 1992 and 1995.2

 These reports, most of which were 

prepared by Charles Alexander, addressed a wide range of topics such as 

replacing the 2000 Census long form, collecting intercensal population 

data, and integrating the ACS with existing household surveys. The reports 

on replacing the long form identified the key issues that needed testing, 

and they served as the primary input to the Census Bureau’s ACS test 

program. These issues included those subsequently tested by the Census 

Bureau as well as the unresolved issues we identify in this report. 

Following the CM reports, Census Bureau staff presented papers from 

1995 through 2001 on ACS testing at various professional association and 

similar meetings, as well as at a 1998 symposium on the ACS sponsored by 

the Census Bureau.3

 For example, the 1995 paper by Love, Dalzell, and 

Alexander discussed issues related to the evaluation of the 1996 test site 

 1

The Census Bureau also prepared a number of internal papers that evaluated the results of 

the 2000 Census long form and recommended changes that applied to the ACS. We discuss 

some of these papers in this report. 

2

Most of the papers in this series are not available to the public (a few are on the Census 

Bureau’s ACS Web site at http://www.census.gov/acs/www/), but the Census Bureau 

provided us with a complete set. 

3

Some of the papers from this March 25, 1998, symposium are available on the Census 

Bureau’s ACS Web site; several presented information from the 1996 ACS testing. 

Appendix IV: Continuous Measurement ACS 

Testing and Development Program 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 53 GAO-05-82 American Community Survey 

results, expressing concern about population controls and residence rules 

as well as the need for consultation with users.4

 They reported that the 

Census Bureau was planning to conduct research using data from the 

1996 test sites to produce controls at the census tract and block group 

level. They also noted that the Census Bureau would need to conduct 

research on the residence rule. 

Alexander and Wetrogan also discussed the issue of population controls in 

their 2000 paper.5 They reviewed possible methods for using ICPE to 

develop controls for the ACS and discussed using ACS estimates on the 

foreign-born U.S. population to improve the Census Bureau’s foreignmigration component of the intercensal estimates. (They reported that this 

effort would be part of what the Census Bureau had previously referred to 

as the Program of Integrated Estimates.) They also noted the need to 

consult with users on how to present information on the differences in 

ACS controls and ICPE in ACS publications. 

Several papers have focused on the key role of evaluating differences 

among the ACS test data, census long-form data, and CPS data. Alexander, 

Dahl, and Weidman reported in 1997 that during the demonstration period, 

they would be working closely with experts familiar with specific test sites 

to learn about the quality of the ACS estimates.6

 For example, they 

reported that the Census Bureau would be looking into sources of 

differences between the 1999–2001 ACS test-site average estimates and the 

2000 Census long-form results and using the results of differences between 

the 2000–02 national sample and the 2000 long form to generate modelbased estimates for small geographic areas. The authors noted that these 

model-based estimates, based largely on information from test sites, would 

be used to interpret changes between 2000 and future ACS estimates. 

 4

Susan Love, Donald Dalzell, and Charles Alexander, “Constructing a Major Survey: 

Operational Plans and Issues for Continuous Measurement,” presented at the annual 

American Statistical Association meeting, Orlando, Florida, August 16, 1995. 

5

Charles H. Alexander and Signe Wetrogan, “Integrating the American Community Survey 

and the Intercensal Demographic Estimates Program,” presented at the Joint Statistical 

Meetings, Indianapolis, Indiana, August 14, 2000. 

6

Charles H. Alexander, Scot Dahl, and Lynn Weidman, “Making Estimates from the 

American Community Survey,” presented at the Annual American Statistical Association 

Meeting, Anaheim, California, August 13, 1997. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 54 GAO-05-82 American Community Survey 

In another 1997 paper, Davis and Alexander reported the Census Bureau’s 

action plan for evaluation studies.7

 They called for evaluating the results of 

all test sites and releasing the expert review of the analyses of the 

differences between the 1999–2001 ACS and the 2000 Census long form. 

The schedule called for releasing this information before beginning the 

implementation of the full ACS. Alexander’s 1998 paper on completed 

research, research in progress, and planned research included among the 

four items for planned research a “close study of differences between 

1999–2001 ACS and 2000 long form in comparison areas.”8

The quality of the ACS measures of income was the subject of the paper 

Posey and Welniak presented at the Census Bureau’s 1998 symposium on 

the ACS.9

 They compared income reported in the 1996 ACS and 

1990 Decennial Census in an effort to evaluate the quality of the ACS 

income data. One of the adjustments they made to compare the two series 

was for the effect of inflation between 1990 and 1996. They noted that the 

results of the comparisons indicated a potential problem that may relate to 

the ACS inflation adjustment. (They described the calculation of the 

adjustment, which is based on the CPI, but did not provide a rationale for 

using the adjustment in the ongoing ACS data.) 

Alexander and two BLS staff reported in 1999 on the potential for using 

the ACS to improve labor force data from the CPS for state and smaller 

geographic levels.10 They stressed that to develop procedures for making 

 7

Mary Ellen Davis and Charles H. Alexander, “The American Community Survey: The 

Census Bureau’s Plan to Provide Timely 21st Century Data,” Delaware Dataline, Summer 

1997. U.S. Census Bureau, American Community Survey, Advanced Methodology, Papers 

and Presentations, http://www.census.gov/acs/www (June 3, 2004). 

8

Charles Alexander, “Recent Developments in the American Community Survey,” presented 

at the American Statistical Association Meeting, Dallas, Texas, August 12, 1998. U.S. Census 

Bureau, American Community Survey, Advanced Methodology, Papers and Presentations, 

http://www.census.gov/acs/www (June 3, 2004). 

9

Posey and Welniak, “Income in the ACS: Comparisons to the 1990 Census.” 

10Shail Butani, Charles Alexander, and James Esposito, “Using the American Community 

Survey to Enhance the Current Population Survey: Opportunities and Issues,” presented at 

the 1999 Federal Committee on Statistical Methodology Research Conference, Arlington, 

Virginia, November 15–17, 1999. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 55 GAO-05-82 American Community Survey 

these improvements, much research would be needed to evaluate 

differences between the ACS and CPS.11

The last research paper in this period was Alexander’s 2001 paper focusing 

on the origins of the CM methodology and its developers.12 He discussed 

the ACS in the context of the methodology, noting several important 

differences related to the nature of the ACS. He included a review of the 

Census Bureau’s testing and evaluation program, noting that the ACS testsite program had been expanded and that national sample supplementary 

surveys had been added. He said that these test data would be compared 

with the 2000 Census long-form data and that in 2001 and 2002, the 

Supplementary Survey would be used as part of the transition to the ACS. 

He also pointed to unresolved issues relating to the residence rule and the 

multiyear averages, because they would provide users with multiple 

estimates for geographic areas with populations larger than 20,000. 

Between 2001 and 2003, the Census Bureau has issued three official 

reports and one internal report on the status of the ACS testing and 

development program. In Demonstrating Operational Feasibility, 

published in July 2001, the Census Bureau gave a brief history of the ACS 

development program, which by 2001 was focused on preparing for full 

implementation in 2003 (although the Census Bureau later revised this to 

2004) but on its operational feasibility, using data from C2SS.13 On the 

basis of the Census Bureau’s analysis of the results of its tests of operation 

feasibility, it reported the tests a success. However, it recognized that 

more evaluation on measures of data quality was necessary, as well as on 

differences between ACS and 2000 Census long- form data. The Census 

Bureau announced that over the next 2 years it would issue reports 

comparing data from the 2000 Census long form at the national, state, and 

 11To assist in this research, BLS wrote a contract with Wayne Vroman of the Urban Institute 

for his 2003 report, “Comparing Labor Market Indicators from the CPS and ACS.” 

12Charles H. Alexander, “Still Rolling: Leslie Kish’s ‘Rolling Samples’ and the American 

Community Survey,” in Proceedings of Statistics Canada Symposium 2001: 

October 16–19 (Ottawa, Canada: Statistics Canada, 2002). 

13U.S. Census Bureau, Meeting 21st Century Demographic Data Needs, Report 1, 

Demonstrating Operational Feasibility (Washington, D.C.: July 2001). C2SS, conducted as 

part of the 2000 Census, was a national survey of about 700,000 households and designed to 

test the operational feasibility of collecting long-form data at the same time as, but 

separately from, the Decennial Census. Its questionnaire was essentially the same as the 

long form. The survey has been conducted annually since 2000. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 56 GAO-05-82 American Community Survey 

smaller geographic areas with data from the C2SS and the ACS 

development program. 

Demonstrating Survey Quality, published in May 2002, focused on 

measures of C2SS survey quality, summarizing sampling and nonsampling 

error levels in both C2SS and the 31 ACS test sites.14 The Census Bureau 

used available, generally accepted measures of quality.15 On the basis of its 

analysis of the results of these quality tests, the Census Bureau reported 

the tests a success. This conclusion rested on test results that showed the 

C2SS program capable of providing reliable long-form data. 

As in the July 2001 report, the Census Bureau recognized that more 

evaluation was necessary on measures of data quality as well as on 

differences between ACS and 2000 Census long-form data and the detailed 

estimates produced from C2SS. The Census Bureau repeated its 

commitment that over the next year and a half, it would release other 

reports to (1) analyze in detail basic demographic characteristics 

(relationship, race, tenure) produced from the C2SS at the national and 

state levels, including comparisons between C2SS and Census 2000; 

(2) describe the data release plan and products for the ACS and the 

usability and accessibility of estimates resulting from ACS methods; and 

(3) give several detailed analyses of selected social, economic, and 

housing characteristics (education, income, commuting patterns), 

including comparisons between C2SS and Census 2000 at the national and 

some subnational levels. 

In June 2002, shortly after Demonstrating Survey Quality was released, a 

team of Census Bureau specialists who had been working on the ACS for 

several years prepared an internal report on testing. They presented a 

revised program development plan and identified key questions to be 

answered in testing the adequacy of the ACS in replacing the Decennial 

Census long form. Their plan included the preparation of a series of nine 

 14U.S. Census Bureau, Meeting 21st Century Demographic Data Needs, Report 2, 

Demonstrating Survey Quality (Washington, D.C.: May 2002). 

15U.S. Office of Management and Budget, Measuring and Reporting Sources of Errors in 

Surveys, Statistical Policy Working Paper 31 (Washington D.C.: July 2001). 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 57 GAO-05-82 American Community Survey 

evaluation reports over 2 years.16 The reports that evaluated differences 

between the 2000 Census short-form data (100 percent reported) and 

corresponding C2SS items were included in Demonstrating Survey 

Quality. Three reports to be completed between October 2002 and 

January 2003 would evaluate differences between the detailed housing, 

social, and economic characteristics between C2SS and the 2000 Census 

long form, as described in Demonstrating Survey Quality. (Although this 

schedule was later extended to the end of 2003, these three reports still 

had not been released when we prepared our final draft of this report.) 

Finally, the team’s plan included a report that would focus on the 

comparisons of 3-year averages for the basic demographic, housing, social, 

and economic characteristics from the C2SS and ACS test sites and 

comparable estimates in the 2000 Census long form. The last report in the 

plan would compare data for 2001 and 2002 with measures shown in 

Demonstrating Operational Feasibility. The plan did not provide 

completion dates for these reports. 

American Community Survey Operations Plan, Release 1, published in 

March 2003, identified research projects to be completed in preparation 

for full implementation of the ACS.17 Two projects were on “weighting and 

estimation,” which covered the methodology for using independent 

population and housing controls, and on “program of integrated 

estimates,” which covered the calculation of these controls from the 

Census Bureau’s intercensal population estimates program. The 

operations plan also reported on the schedule for completing several 

comparison and evaluation projects with ACS and 2000 Census long-form 

data discussed in Demonstrating Survey Quality. It discussed the need to 

evaluate multiyear estimates from the supplementary surveys to 

demonstrate the usability, reliability, and stability of ACS estimates over 

 16In 2000, the Census Bureau established an ACS Research and Evaluation Steering 

Committee to develop a series of reports on key results from the ACS development 

program. A team was to manage the program and identify key questions whose answers 

would demonstrate the adequacy of the ACS as a replacement for the Decennial Census 

long form. See U.S. Census Bureau, American Community Survey Development Report 

Series Program Plan (Washington, D.C.: rev. June 12, 2002), p. 5. 

17U.S. Census Bureau, American Community Survey Operations Plan, Release 1. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 58 GAO-05-82 American Community Survey 

time, and it stated that a report comparing 3-year ACS data with data 

from the 2000 Census long form would be released in mid-2003.18

The Census Bureau reported that the results of these research projects 

would not be available in 2004. Instead, it said, it would use interim 

procedures, taking “extensive long-term investigation and 

experimentation” to develop final procedures.19 For the ACS weighting and 

estimation project, the Census Bureau reported that it would be using an 

interim adjustment to adjust the intercensal population and housing 

characteristics estimates to the ACS residence concept. The Census 

Bureau reported that ACS estimates of occupied housing units, 

households, and householders should agree at all geographic levels. 

For the program of integrated estimates project, the operations plan 

discussed the need for more research to introduce improvements to the 

estimates from ICPE. (The ACS estimates are weighted to a population 

benchmark, either the most recent Decennial Census results or the most 

recent ICPE estimates.) The Census Bureau reported that because the 

accuracy of the intercensal estimates is important to overall ACS 

accuracy, it is important to use ACS data wherever appropriate to improve 

the intercensal estimates. The plan for the program on integrated 

estimates will use information from the 2000 Census, more current ACS 

distributions of population characteristics, and administrative records to 

produce improved population and housing unit estimates for all areas, 

including small areas. The plan also discussed improving housing 

characteristics by incorporating ACS distributions of local area vacancy 

rates and household characteristics into statistical models to better 

estimate subcounty populations. No time schedule for completing the 

research was provided. 

Finally, the March 2003 American Community Survey Operations Plan, 

Release 1 discussed a plan in the ACS to cover group quarters. Persons 

living in group quarters live in places that the Census Bureau does not 

classify as housing units—for example, nursing homes, prisons, college 

dormitories, military barracks, institutions for juveniles, and emergency 

and transitional shelters for the homeless. Such residences accounted for 

 18In April 2003, the Census Bureau let a contract with local experts to study and evaluate 

selected differences between 1999–2001 averages from four test sites and corresponding 

2000 long-form data. 

19U.S. Census Bureau, American Community Survey Operations Plan, Release 1, p. 36. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 59 GAO-05-82 American Community Survey 

roughly 2.8 percent of the population in 2000. Although data on group 

quarters were collected at the test sites beginning with 1999, data were not 

collected in C2SS or subsequent supplementary surveys. The operations 

plan discussed the use of an updated Census 2000 Special Places file for 

the sampling frame for the full ACS. In this case, the plan noted, training 

field representatives on collecting data from this population is to begin in 

October 2004, so that full data collection production can begin in January 

2005. 

Census Bureau staff made a presentation on comparison and evaluation 

reports at the April 2003 meetings of the Census Advisory Committee. The 

paper’s author reported that work was under way on the comparison 

reports noted in the March 2003 operations plan, and she described the 

methodology to be used to evaluate differences between the 2000 long 

form and C2SS. She also reported that the results of the comparisons 

would be used to identify how the ACS should be improved but that 

additional research would be needed to address consistency over time 

between the 2000 Census and the full ACS. She stressed the importance of 

evaluating consistency “in educating users on the transition from the 

decennial census sample estimates to the ACS estimates.”20

With regard to the comparison report of selected demographic, housing, 

social, and economic characteristics of 3-year estimates from the ACS test 

sites to the 2000 Census, the Census Bureau let four contracts with local 

experts to conduct comparisons of 3-year averages of ACS data for 

1999–2001 for selected test sites with selected 2000 Census long-form data 

as well as 2000 Census population and housing unit characteristics. The 

comparisons, prepared at the county and census tract levels, would be 

made for measures of data quality (self-response rates, sample unit 

nonresponse rates, item nonresponse rates, and sample completeness 

ratios), as well as for data levels (counts, percentages, means, and 

medians) for demographic, social, economic, and housing characteristics. 

In summer 2003, Census Bureau staff presented a number of research 

papers on the ACS at the annual Joint Statistical Meetings. Papers 

evaluated differences between long-form and C2SS data items, such as 

persons with disabilities, educational attainments, and income. Most of the 

 20Deborah H. Griffin, “Comparing Characteristics from the American Community Survey 

and Census 2000: Methodology,” presented at Census Advisory Committee of Professional 

Associations Meetings, Washington, D.C., April 10–11, 2003, p. 2. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 60 GAO-05-82 American Community Survey 

papers that provided comparisons with long-form data indicated whether 

differences were statistically significant for every comparison. 

Comparisons were presented at a variety of geographic levels (national, 

state, and test site levels). Some papers cited operational differences as 

possible explanatory factors, but information was not presented using a 

standard set of factors. 

The Census Bureau published ACS-2010 Census Consistency Review 

Plan, an internal document, at the beginning of October 2003. Its purpose 

was to identify methods for major operations used in the ACS and for the 

2010 Census that were likely to lead to inconsistent results and to 

recommend ways to address these inconsistencies.21 Papers prepared on 

these operations were to discuss how an issue might result in 

inconsistencies between the ACS and 2010 Census results and to set forth 

options for dealing with consistency issues, including a research process. 

The plan identified residence rules and group quarters as two topics. It did 

not discuss completing the work in time to incorporate it into the full ACS 

in the next several years. 

Also in October 2003, the Census Bureau made two public announcements 

related to the ACS development plan at the Census Advisory Committee 

meetings. Two papers related directly to projects described in American 

Community Survey Operations Plan, Release 1. In “Enhancing the 

Intercensal Population Estimates Program with ACS Data: Summary of 

Research Projects,” Weidman and Wetrogan reported on research to 

improve the intercensal estimates by using ACS data for two “high 

priority” areas—international migration and internal migration. This work 

was being conducted within the Program of Integrated Estimates.22 The 

second paper described options for determining population control 

weights for ACS implementation in fall 2004 but did not indicate that 

research was under way to determine the effect of the options.23

 21U.S. Census Bureau, ACS-2010 Consistency Review Plan (Washington, D.C.: October 1, 

2003). 

22Lynn Weidman and Signe Wetrogan, “Enhancing the Intercensal Population Estimates 

Program with ACS Data: Summary of Research Projects,” Census Advisory Committee of 

Professional Associations meeting, Washington, D.C., October 23, 2003. 

23Navarro, “American Community Survey: Use of Population Estimates as Controls in the 

ACS Weighting,” presented at Census Bureau Advisory Committee of Professional 

Associations meeting, Washington, D.C., October 23, 2003. 
Appendix IV: Continuous Measurement ACS 

Testing and Development Program 

Page 61 GAO-05-82 American Community Survey 

Another source of information related to ACS development was the 

various reports prepared as part of the Census 2000 Testing, 

Experimentation, and Evaluation Program. Schneider’s January 

2004 report compared employment, income, and poverty estimates from 

the 2000 Census long form and the CPS.24 From this comparison, the 

author concluded that this work should be continued in an effort to use 

the results of the comparisons to improve consistency between data 

collected in the CPS and data in the ACS; the ACS uses the same questions 

as the 2000 long form. The author also identified for additional research 

long-form questions that performed badly, based on a reinterview survey. 

From May to July 2004, the Census Bureau released seven ACS evaluation 

reports. Four reports compared data from the 2000 Census long form and 

the C2SS at the national level. Two reports compared these long-form data 

with 1999-2001 data from the ACS test sites for selected counties and one 

of these compared these data at the tract level. The other report reviewed 

operational data from the 2001 and 2002 supplementary surveys. In most 

of the reports comparing long-form and ACS data, the Census Bureau 

identified additional work that was needed to improve the quality of the 

ACS estimates or to help explain differences between the two sets of data 

for 2000. As noted earlier, these comparisons were limited to the national 

level. (The seven new reports are listed in the bibliography.) 

 24Paula Schneider, Content and Data Quality in Census 2000, Census 2000 Testing, 

Experimentation, and Evaluation Program Topic Report No. 12 (Washington, D.C.: U.S. 

Census Bureau, January 22, 2004). 
Appendix V: Current Status of Unresolved 

Issues 

Page 62 GAO-05-82 American Community Survey 

According to the Census Bureau’s plans, the calculation of independent 

controls for population characteristics (age, sex, race, and ethnicity) and 

housing characteristics for the full ACS will require a significantly 

different methodology from that used for the ACS supplementary surveys. 

Controls will be needed at the same level of geographic area detail as 

those that were used for the 2000 Census long form and will need to reflect 

the new concepts of residence and reference period underlying the ACS. 

For the annual ACS supplementary surveys, these characteristics were 

used from ICPE as the independent controls. ICPE uses Decennial Census 

short-form data as benchmarks and administrative record data to 

interpolate between and extrapolate from the census benchmarks.1

 The 

program provides “official” annual estimates of population and housing 

characteristics at the county level, and for some subcounty levels, as of 

July 1 of each year, using the usual residence concept for seasonal 

residents. The program also provides annual estimates of total population 

and housing units for all areas of general-purpose government, such as 

cities, villages, towns, and townships.2

 Table 3 shows information on the 

calculation of the independent controls used for the 2000 Census long 

form, the ACS supplementary series, and the fully implemented ACS 

through 2012. 

 1

ICPE develops and disseminates annual estimates of the total population and the 

distribution by age, sex, race, and Hispanic origin for the nation, state, counties, and 

functioning government units. The program is authorized by 13 U.S.C. §181, which requires 

the production of “current data on total population and population characteristics.” 

2

For additional details, see U.S. Census Bureau, “Estimates and Projections Area 

Documentation: Subcounty Total Population Estimates,” http://www.census.gov. 

Appendix V: Current Status of Unresolved 

Issues 

Independent Controls 

for Population and 

Housing 

Characteristics 
Appendix V: Current Status of Unresolved 

Issues 

Page 63 GAO-05-82 American Community Survey 

Table 3: The 2000 Census Long Form and ACS Use of Independent Controls for Population and Housing Characteristics 

Survey and 

date 

Source of 

controlsa

Weighting area Items weighed 

Residence 

concept 

Reference 

period Comments 

2000 Census 

long form 

2000 Census About 65,000 areas Population: age group 

(13), sex, race (6), 

Hispanic origin (2). 

Housing: occupied or 

vacant, owner or renter 

Usual Apr. 1, 

2000 

ACS test site 

1999 ICPE 

benchmarked to 

1990 Census 

County Population: age group,b

sex, race (3), Hispanic 

origin (2). Housing: no 

direct use of housing 

weights 

Usual July 1, 

1999 

2000 2000 Census County Population: age group,b

sex, race/ Hispanic 

origin (6), Housing: total 

number of units 

Usual Apr. 1, 

2000 

2001–04c ICPE 

benchmarked to 

2000 Census 

County Population: age group,b 

sex, race/ Hispanic 

origin (6). Housing: total 

units 

Usual July 1, 

2001–04 

ACS supplementary survey 

2000 2000 Census County or county 

combinations 

Population: age group,b

sex, race/ Hispanic 

origin (6). Housing: total 

units 

Usual Apr. 1, 

2000 

2001–04cICPE 

benchmarked to 

2000 Census 

County or county 

combinations 

Population: age group,b

(14), sex, race/ Hispanic 

origin (6). Housing: total 

units 

Usual July 1, 

2001–04 
Appendix V: Current Status of Unresolved 

Issues 

Page 64 GAO-05-82 American Community Survey 

Survey and 

date 

Source of 

controlsa Weighting area Items weighed 

Residence 

concept 

Reference 

period Comments 

Full ACS 

2005–09,dICPE 

benchmarked to 

2000 Census 

adjusted to ACS 

residence concept 

(adjustment 

methodology not 

announced) 

Three options:e

(1) Intercensal 

estimates (usual 

residence) for large 

areas and ACS 

estimates (current 

residence) for small 

areas 

(2) Option 1 but modelbased estimates to 

modify intercensal 

estimates for large 

areas to current 

residence 

(3) Develop methods to 

generate current 

residence estimates for 

all small areas 

Other: Same areas as 

2000 Census long form 

using intercensal 

estimates and detail 

from 2000 census 

Not announced Current Not 

announcedf 

Residence concept 

changes; weighting 

area options part of 

research program 

to determine 

weighting areas for 

use with 3- and 5-

year averages for 

2010 

2010e2010 Census 

adjusted to ACS 

residence concept 

(adjustment 

methodology not 

announced) 

Not announcedg

Not announced Current Not 

announced 

2010 short-form 

data replace ICPE 

estimates 

2011 ICPE 

benchmarked to 

2010 Census 

adjusted to ACS 

residence concept 

(adjustment 

methodology not 

announced) 

Not announcedg

Not announced Current Not 

announced 

2012 ICPE 

benchmarked to 

2010 Census 

adjusted to ACS 

residence concept 

(adjustment 

methodology not 

announced) 

Not announcedg Not announced Current Not 

announced 

Source: GAO analysis of Census Bureau documents. 
Appendix V: Current Status of Unresolved 

Issues 

Page 65 GAO-05-82 American Community Survey 

a

The Intercensal Population Estimates Program (ICPE) develops and disseminates annual estimates 

of the total population and the distribution by age, sex, race, and Hispanic origin for the nation, state, 

counties, and total population for subcounty functioning government units. ICPE is authorized by 13 

U.S.C. §181, which requires the production of “current data on total population and population 

characteristics.” ICPE estimates, benchmarked to the latest Decennial Census counts, are compiled 

using administrative record data on births, deaths, and migration. Because they are benchmarked to 

the census, they reflect the usual residence concept. They are adjusted to reflect the counts as of 

July each year. 

b

Not available. 

c

Assumes that test program and supplementary surveys end after 2004

d

When 2010 Census estimates become available, ICPE estimates beginning with 2001 will be revised 

to reflect the new benchmark. There is no announced use of revised ICPE estimates to revise 

previously published ACS estimates. 

e

The three options are from Alfredo Navarro, “American Community Survey: Use of Population 

Estimates as Controls in the ACS Weighting,” presented at Census Bureau Advisory Committee of 

Professional Associations meeting, Washington, D.C., October 23, 2003. 

f

One of the Department of Commerce comments on our draft report stated that the Census Bureau 

would be using July 1 as the reference period for a given year’s ACS annual average. 

g

There is no announced use of the tract or block group data from the 2010 census. 

Using ICPE for the ACS supplementary surveys, the Census Bureau 

prepared controls for counties, or combinations of counties. As shown in 

table 3, for the residence concept, controls from the 2000 Census and 

ICPE, which were based on the usual residence concept, were used. The 

reference period for the ACS test program for all years except 2000 was 

for July 1; for 2000, it was for April 1. (Controls for the 2000 Census long 

form also were for April 1.) 

For the full ACS, the Census Bureau will use controls based on the current 

residence concept. According to the Census Bureau, the current residence 

concept recognizes that the place of residence does not have to be the 

same throughout a year, so that the current residence concept allows the 

ACS data to more closely reflect the actual characteristics of each area. 

The Census Bureau will use the current residence concept because the 

ACS is conducted every month and produces annual averages rather than 

point-in-time estimates, as the Decennial Census does. Also, because the 

ACS data are collected monthly, it will be necessary to use independent 

controls that define the reference period as the average for the year using 

a July 1 reference period. 

To produce ACS estimates for the full sample, the Census Bureau will 

need new methodologies for calculating independent controls. For the 

first annual estimates, for 2005, a methodology will be needed to provide 

ACS-defined controls for all places with population of 65,000 or more, 

including those for which intercensal population estimates are not 
Appendix V: Current Status of Unresolved 

Issues 

Page 66 GAO-05-82 American Community Survey 

available. For the 2005–07 estimates, which will be used to calculate the 

first multiyear averages, a methodology for controls for geographic areas 

with populations between 20,000 and 65,000 will be needed. For the 

2008–12 estimates, a methodology for controls down to the geographic 

levels used for the 2000 Census long form will be needed. Finally, when 

the population and housing characteristics data from the 2010 Census 

short form become available and are incorporated into the ICPE estimates, 

another new methodology will be needed to revise the ACS controls for 

2010.3

The Census Bureau also has reported that it is not planning to revise 

earlier years’ ACS data for consistency with revised 2010 estimates unless 

the inconsistencies between the 2010 ICPE and 2010 Census 

characteristics were significant. Table 4 shows the differences between 

population estimates at the county level for 2000 using ICPE based on the 

1990 Census and the corresponding data from the 2000 Census. In 

2000, the population estimates for almost 20 percent of the counties 

differed by more than 5 percent. For counties whose population was 

smaller than 20,000, almost 25 percent had similar differences. 

 3

The initial ACS estimates for 2010 are to be released before the 2010 Census-based ICPE 

estimates are available. 
Appendix V: Current Status of Unresolved 

Issues 

Page 67 GAO-05-82 American Community Survey 

Table 4: Population Comparison for Counties in 2000 from ICPE and 2000 Census by County Size 

 Number of counties with ratio of 

County 

populationa Total 

Less than 

0.90 

0.90– 

0.949

0.95–

0.999

1.00–

1.049

1.05–

1.099

1.10 or 

more 

Percentage of 

counties with ratio 

less than 0.95 or 

more than 1.05

All counties 3,141 118 384 1,722 809 88 20 19

Less than 20,000 1,348 67 174 672 355 63 17 24

20,000 to less 

than 65,000 1,046 41 112 576 294 20 3 17

65,000 to less 

than 250,000 

516 9 62 315 125 5 0 15

250,000 or more 231 1 36 159 35 0 0 16

Sources: Census Bureau reports and GAO analysis. 

Note: Initial intercensal estimates for 2000 were benchmarked to the 1990 Census; counties include 

county equivalents, such as parishes in Louisiana. 

a

Population classes reflect level of geographic area detail to be calculated from ACS. For example, 

geographic areas with populations smaller than 20,000 will be available using 5-year averages. 

Census Bureau staff had long recognized the need for new methodologies 

to develop independent controls for the ACS. For example, a 1995 paper 

by Love, Dalzell, and Alexander, discussing issues related to evaluating the 

1996 test site results, expressed concern about independent controls and 

residence rules, as well as the need for consultation with users.4

 In 

1998, the Census Bureau sponsored a conference on the quality of ACS 

data for rural data users. In the final report on this conference, the Westat 

authors concluded that the Census Bureau needed to continue and expand 

its contacts with stakeholders and to conduct additional research on 

several issues, including independent controls.5

 Alexander and Wetrogan 

also discussed this issue at the 2000 Joint Statistical Meetings when they 

 4

Susan Love, Donald Dalzell, and Charles Alexander, “Constructing a Major Survey: 

Operational Plans and Issues for Continuous Measurement,” presented at the annual 

American Statistical Association meeting, Orlando, Florida, August 16, 1995. 

5

This May 14–15, 1998, conference was held in response to U.S. Senate Appropriations 

Committee Report 105-48, 105th Cong., 1st sess. (July 16, 1997), title II, p. 64, which had 

stated that “The outside evaluator should review the ACS to determine whether there is an 

antirural bias in its design.” Graham Kalton and others prepared the conference report for 

the Census Bureau: The American Community Survey: The Quality of Rural Data 

(Rockville, Md.: Westat, June 29, 1998). 
Appendix V: Current Status of Unresolved 

Issues 

Page 68 GAO-05-82 American Community Survey 

reviewed possible methods for using ICPE estimates.6 They also noted the 

need to consult with users on how to present information on the 

differences in ACS controls and ICPE in ACS publications. 

Census Bureau staff also recognized that the new ACS would create 

differences between (1) ACS population and housing characteristics data 

and the corresponding “official” data from the Decennial Census and 

(2) ACS population and housing characteristics data and the “official” 

ICPE population estimates, which are benchmarked to Decennial Census 

data. They also recognized that the creation of new controls for the ACS 

would result in inconsistencies between ACS data and data from federal 

household surveys, such as the CPS, whose population and housing 

characteristics are also based on the Decennial Census and ICPE 

estimates. Such differences might hinder the use of ACS data to expand 

and improve small geographic area estimates based on the other surveys. 

(CPS provides official national estimates of labor force information, such 

as the unemployment rate and income estimates used to calculate the 

number of persons in poverty.) 

In March 2003, the Census Bureau announced that it did not have a final 

methodology and that such methodologies would not be established for 

several years. In March 2003 in American Community Survey Operations 

Plan, Release 1, the Census Bureau identified research projects to be 

completed in preparation for full implementation of the ACS. One of these 

projects, “weighting and estimation,” covered the methodology for 

calculating the independent controls for the ACS; a second, “program of 

integrated estimates,” covers the calculation of these controls from the 

ICPE. This plan also reported that the results of these research projects 

would not be available in 2004 to begin implementing them with the start 

of the full ACS. Instead, the Census Bureau said it would use interim 

procedures and that it would take “extensive long-term investigation and 

experimentation” to develop final procedures. 

For the weighting and estimation project, the Census Bureau reported that 

it would be using an interim adjustment to adjust the intercensal 

population and housing characteristics estimates to the ACS residence and 

reference period concepts. This project would include research to 

examine the need to achieve agreement between the estimates of occupied 

 6

Alexander and Wetrogan, “Integrating the American Community Survey and the 

Intercensal Demographic Estimates Program.” 
Appendix V: Current Status of Unresolved 

Issues 

Page 69 GAO-05-82 American Community Survey 

housing units, households, and householders at all geographic levels. The 

Census Bureau reported that work on the project to revise and simplify 

the weighting methodology began in early 2003, that preliminary papers 

documenting the revisions might be available by summer 2004, and that 

research would continue for several years. 

For the program of integrated estimates project, the operations plan 

discussed the need for more research to introduce improvements to the 

ICPE estimates using information from the 2000 Census, more current 

ACS distributions of population characteristics, and administrative 

records to produce improved population and housing unit estimates for all 

areas, including small geographic areas. The plan also discussed improving 

the housing characteristics. ACS distributions of local area vacancy rates 

and household characteristics can be incorporated into statistical models 

that use distributions of housing unit characteristics to better estimate 

subcounty populations. No time schedule was provided for completing the 

research.7

In October 2003, Census Bureau staff presented a paper at the Census 

Advisory Committee meetings that described the options being considered 

to convert the ICPE estimate to the current residence concept.8

 The paper 

described options for determining controls for ACS implementation in fall 

2004 but did not indicate that research was under way to determine the 

options’ effects. A second paper at the same meetings reported on 

research to improve the intercensal estimates by using ACS data for two 

“high priority” areas—international migration and internal migration. This 

work was being conducted as part of the Program of Integrated 

Estimates.9

Although the latest NAS report on the ACS does not specifically note 

issues relating to independent controls, we asked experts who had 

participated in preparing NAS reports, as well as other experts in small 

area data, the following question about ACS weighting: 

 7

ACS data on foreign-born persons were used to estimate the national levels of 

international migration that were incorporated into the intercensal estimates for 2003, 

based on the 2000, 2001, and 2002 ACS. 

8

Navarro, “American Community Survey.” 

9

Weidman and Wetrogan, “Enhancing the Intercensal Population Estimates Program with 

ACS Data.” 
Appendix V: Current Status of Unresolved 

Issues 

Page 70 GAO-05-82 American Community Survey 

“Given the newly benchmarked intercensal estimates, the following question arises 

regarding the use of the 2010 Census data in the ACS: Should ACS estimates continue to be 

controlled to 2010 Census data at the county or county group level and differences between 

the ACS and census population counts and characteristics allocated proportionately to the 

tract or block group levels? Or should ACS estimates be controlled to 2010 Census data at 

the tract and block group level, as would have been the case with a long form?” 

All the experts agreed that the ACS should be controlled to the decennial 

census, but several noted that they had not thought about the issue and 

had not heard anything from the Census Bureau on the issue. (The experts 

are listed in app. I.) 

The Census Bureau has identified operational issues with the ACS test 

programs, primarily from information from evaluation studies on the 

2000 Decennial Census and Census Bureau staff research papers on 

comparisons between data collected in the ACS 2000 supplementary 

survey and the 2000 Decennial Census long form. These issues include 

problems with questionnaire design, nonresponse followup, and data 

capture, as well as coverage of persons living in group quarters. 

In January 2004, the Census Bureau released the results of a key 

evaluation study of 2000 Decennial Census long-form data, using a 

reinterview survey.10 The study identified problems with long-form 

questions, which are the same as those used for the ACS, and proposed 

several research efforts based on a statistical evaluation of the quality of 

the responses to each question. For questions identified as having 

significant quality problems, the study recommended research on the 

design of the form and placement of the questions and suggested using 

cognitive experts in testing revised questions. The study also 

recommended that the Census Bureau and BLS work on the ACS 

employment and unemployment questions to ensure that they would 

complement the BLS local area unemployment statistics program. 

The Census Bureau also conducted a study to evaluate the design of the 

ACS questions that are needed to implement the residence concept and 

reference period for the ACS.11 The study suggested that additional testing 

 10Schneider, Content and Data Quality in Census 2000. 

11Theresa J. DeMaio and Kristen A. Hughes, “Report of Cognitive Research on the 

Residence Rules and Seasonality Questions on the American Community Survey,” U.S. 

Census Bureau, Statistical Research Division, Washington, D.C., July 2003. 

Operational Issues 
Appendix V: Current Status of Unresolved 

Issues 

Page 71 GAO-05-82 American Community Survey 

was needed for the questions about multiple residences (currently, the last 

set of questions in the housing section). It noted “that asking these 

questions on a person basis may produce different and probably better 

data than asking them on a household basis.”12 The study was limited in 

scope and did not assess how accurately ACS respondents assign persons 

associated with the household to a current residence. 

In the ACS, the Bureau uses “In the past 12 months . . .” whereas the 

Census Bureau used “In 1999 . . .” for the long form. Because the reference 

date is not fixed, it is important for a respondent to supply the date that 

the ACS questionnaire filled out. Otherwise, it cannot be determined 

whether there is an inconsistency in an ACS questionnaire received in late 

April 2004 that lists a resident aged 10 with a birthdate of April 15, 1993.13

Census Bureau staff also discussed operational issues in research papers, 

based on evaluations of comparisons between 2000 Decennial Census 

long-form and ACS 2000 supplementary survey data for selected items 

presented at the 2003 Joint Statistical Meetings. A paper on income data 

identified the new question on the reference period as a potential source 

of problems, even though an additional instruction had been added to the 

ACS questionnaire in 1999.14 The authors expressed concern that some 

ACS respondents may misinterpret the question on “income in the past 

12 months” as a request for monthly income instead of income during the 

previous year. The paper also included recommendations for additional 

research on the effect of the data capture methods. For the 2000 long 

form, all data items were entered with an automated optical character 

recognition procedure; data from the ACS will be manually keyed. 

Another paper, presented at the same 2003 meetings, that evaluated 

differences in the data on disabled persons found large and significant 

differences at the national level and also recommended that new questions 

 12DeMaio and Hughes, “Report of Cognitive Research on the Residence Rules and 

Seasonality Questions,” pp. 9–10. 

13In contrast, a 2000 Census questionnaire received in late April 2000 that listed a resident 

aged 11 with an April 15, 1989, birthdate would be considered inconsistent because the 

person was aged 10 on census day. 

14Kirby G. Posey, Edward Welniak, and Charles Nelson, “Income in the American 

Community Survey: Comparisons to Census 2000,” presented at the Joint Statistical 

Meetings, San Francisco, California, August 7, 2003. 
Appendix V: Current Status of Unresolved 

Issues 

Page 72 GAO-05-82 American Community Survey 

be tested.15 Additional areas were identified for further research, based on 

evaluations of questions such as educational enrollment, ancestry, and 

grandparents caring for grandchildren. These areas included specific 

facets of the mailout-mailback system and nonresponse followup. For 

example, nonresponse follow-up for the 2000 long form was conducted for 

all nonrespondents, but for the ACS test program and for the full ACS, 

nonresponse follow-up will be conducted for a sample of one-third on all 

nonrespondents. 

The Census Bureau also has discussed issues with the expansion of ACS 

coverage to include persons living in group quarters—for example, nursing 

homes, prisons, college dormitories, military barracks, institutions for 

juveniles, homeless shelters.16 In October 2002, it informed its advisory 

committee members of the formation of a special planning team to 

address issues on the definition of group quarters and duplication in the 

address file. From the minutes of this meeting, it appears that this team 

will focus on group quarters in the context of the 2010 Census short form. 

In the ACS March 2003 operations plan, the Census Bureau reported on a 

new project to cover group quarters in the full ACS.17 The Census Bureau 

reported that the special project was needed because of the special 

challenges of developing an updated address list; in the past, such a list 

had been updated only once a decade. According to the Census Bureau, 

tests on the new list were to be completed in time for use in the full ACS in 

January 2005. In addition, an internal planning document issued in 

October 2003 identified group quarters (and residence rules) as special 

problems and instructed staff to provide recommendations on the 

collection of data on them in January 2004.18 Usually, the Census Bureau 

tests new questions. According to recent Census Bureau decisions, those 

 15Sharon M. Stern, “Counting People with Disabilities: How Survey Methodology Influences 

Estimates in Census 2000 and the Census 2000 Supplementary Survey,” presented at the 

Joint Statistical Meetings, San Francisco, California, August 7, 2003. 

16Although data on group quarters were collected at the ACS test sites in 1999 and 2001, 

data on them were not collected in the ACS supplementary surveys, which began in 2000. 

The Census Bureau made this decision to avoid duplication with the 2000 Decennial 

Census and because it lacked funding to cover them in subsequent years. 

17Census Bureau, American Community Survey Operations Plan, Release 1. 

18U.S. Census Bureau, ACS-2010 Consistency Review Plan. 
Appendix V: Current Status of Unresolved 

Issues 

Page 73 GAO-05-82 American Community Survey 

tests would have to be completed so that new questions could be 

incorporated into the 2008 ACS questionnaire.19

The Census Bureau has adjusted all dollar-denominated items from the 

ACS testing programs, such as incomes, housing values, rents, and 

housing-related expenditures, for inflation. For example, ACS data for 

2001 and 2002 released in September 2003 for median household income 

are expressed in 2002 dollars. This practice means that when each added 

year of ACS data is released, all dollar-denominated items for prior years 

will be revised. The Census Bureau makes a similar adjustment for the 

annual income data collected in the CPS. Unlike the ACS, the Census 

Bureau releases annual CPS data without the adjustment. In addition, the 

annual values collected in the ACS were adjusted to the calendar year. It 

will be using the CPI for the annual and monthly adjustments for all 

geographic areas. 

A report prepared for HUD found problems with the adjustment, including 

(1) the lack of a “trending” adjustment in the calculation of annual 

averages, (2) the use of the adjustment for multiyear averages, (3) the 

adjustment for cost of living for data items other than income, and (4) the 

lack of the unadjusted annual data that would enable HUD to use 

alternative methodologies. In addition, research by Census Bureau staff 

questioned the adjustment for incomes when they found that it was a 

probable source of difference between income data from the 

supplementary survey and corresponding data from the CPS and the 

2000 Census long form. 20

The report prepared for HUD provided a detailed review of HUD’s use of 

the ACS for program applications. On the methodology for the inflation 

adjustment, the first step should be a trending adjustment that would 

convert the reported monthly data to a calendar year basis. Discussing 

this omission, the report stated, 

 19 U.S. Census Bureau, 2010 Decision Memorandum Series No. 5. (Washington, D.C.: June 3, 

2004) and 2010 Planning Memorandum Series No. 24 (Washington, D.C.: June 9, 2004). 

20For a complete discussion, see ORC Macro, The American Community Survey: 

Challenges and Opportunities for HUD (Calverton, Md.: Sept. 27, 2002). For a complete 

discussion of the role of the inflation adjustment in differences between the ACS and CPS 

measures of income, see Posey, Welniak, and Nelson, “Income in the American Community 

Survey.” 

Valuation and 

Presentation of 

Dollar-Denominated 

Data Items 
Appendix V: Current Status of Unresolved 

Issues 

Page 74 GAO-05-82 American Community Survey 

“Making an inflation adjustment is not the same as trending. The cost of living adjustment 

assumes that the purchasing power measured at any point in the data collection period 

remains constant throughout the period. For example, assume that the cost of living rises 

by 3 percent a year. If a household reports an annual income of $50,000 in January, a cost 

of living adjustment to the end of the year would increase this income to $51,500, the 

amount needed in December to equal the purchasing power of $50,000 in January. A 

trending adjustment makes no assumption about purchasing power. It attempts to track 

movements in dollar income. Assume that dollar income is growing at 5 percent a year. 

Then a trending adjustment to the end of the year would increase the $50,000 reported in 

January to $52,500 in December.”21

HUD’s second concern was that the methodology the Census Bureau used 

to calculate the adjustment was not appropriate for multiyear averages. 

The HUD report stated, 

“The Census Bureau plans to report income in constant dollars. Income information 

collected in the various months will be adjusted for inflation so that all collected income 

will be expressed in dollars with the same purchasing power, presumably the purchasing 

power of dollars in December of the survey year. For moving average tabulations, all 

income information will be adjusted for changes in purchasing power over the period used 

to calculate the moving average. In other words, income reported by a respondent in the 

first month of a five-year moving average will be adjusted for almost five years of 

inflation.”22

To illustrate this problem, the HUD report gave the following example: 

“The standard Census Bureau tables for areas over 65,000 will tabulate the rents reported 

by respondents over the twelve months during which data were collected. A unit reporting 

a contract rent of $800 in January might actually be paying $850 in December. The standard 

table would record this unit as having a rent of $800. The standard Census Bureau tables 

for areas under 20,000 will tabulate rents reported by respondents over a sixty-month 

period. A unit reporting a contract rent of $800 in the January of the first year might 

actually be paying $1,070 in December of the fifth year. The standard table would record 

this unit as having a rent of $800.”23

 21ORC Macro, p. 16. 

22ORC Macro, p. 44. 

23ORC Macro, pp. 16–17. 
Appendix V: Current Status of Unresolved 

Issues 

Page 75 GAO-05-82 American Community Survey 

Such changes would not be captured with an adjustment based on the allitems CPI. 

The HUD report also noted that the inflation index the Census Bureau 

proposed related to income and not to the other dollar value data, such as 

rent, utility costs, or home value, where a purchasing power concept did 

not meet HUD’s needs. The report concluded that to overcome this 

problem, before HUD could use dollar-denominated data from the ACS, it 

would first have to eliminate the inflation adjustment from the published 

data. The report stated: “For applications that involve trending income, 

HUD users will have to center the ACS information at an appropriate point 

in the collection period and remove the inflation adjustment before 

applying a trending factor.”24 In addition, it noted that 

“The ACS will generate income distributions comparable to those from the decennial 

census, but the distributions will have a feature that will complicate the use of income data 

from the ACS in APP [HUD’s Annual Performance Plan] measures. Whereas the decennial 

long form measures money income, the ACS reports average purchasing power.”25

The report thus recommended that HUD use the unadjusted data—data 

that the Census Bureau had not planned to publish—in order to make the 

changes needed for HUD. 

The validity of the Census Bureau’s inflation adjustment was also 

questioned in research Census Bureau staff conducted to evaluate 

differences between the data reported in the ACS supplementary surveys. 

In a paper presented at the 2003 Joint Statistical Meetings, staff evaluated 

differences between income data from C2SS and the 2000 Census long 

form, as well as the CPS.26 The paper summarized the major differences in 

the income data from these sources in terms of data collection, capture, 

and processing and provided preliminary assessments of their 

contributions to these differences. The authors noted the need for further 

research on the effect of the difference in reference period and the 

inflation adjustment, as well as operational aspects such as data capture. 

With regard to the inflation adjustment, they reported: 

 24ORC Macro, p. 44. 

25ORC Macro, p. 208. 

26See Posey, Welniak, and Nelson. 
Appendix V: Current Status of Unresolved 

Issues 

Page 76 GAO-05-82 American Community Survey 

“If no CPI adjustment had been made to the dollars reported on either Census 2000 or 

C2SS/ACS, the difference between medians at the U.S. level would have been smaller than 

the 4.6 percent shown in Table 3 [omitted]. Instead, the difference would have been 2.5 

percent. Since adjustment clearly played a role in determining the size of the difference 

between Census 2000 and C2SS/ACS estimates, it would be worthwhile to examine the 

costs and benefits of adjusting C2SS/ACS incomes as well as the choice of factors used to 

adjust them.”27

The authors summarized their findings by concluding that “it is clear that 

we are just at the beginning stages of understanding why Census 2000 and 

C2SS income figures differ.”28 They noted that the income comparisons are 

most critical because these Census Bureau data are used in the calculation 

of the number of people in poverty. 

In a December 2003 research paper, Census Bureau staff examined 

concerns about the absence from the official poverty measures of 

adjustment for geographic differences in cost of living. Like the ACS, for 

which the Census Bureau is assuming that the cost of living is the same 

throughout all geographic areas, the poverty measures are based on the 

same assumption. The authors concluded that the use of a poverty 

measure that takes into account geographic differences in housing costs, 

would significantly change the poverty measures in many states.29

One of the Census Bureau’s major justifications for the ACS test programs 

has been its comparing data collected in these programs, and 

corresponding data from the 2000 Decennial Census short and long forms, 

to identify operational problems. Another major justification for the ACS 

test programs has been the use of these comparisons, and comparisons 

with corresponding data from the CPS, to inform users in making the 

transition from the 2000 long form to the ACS. 

The Census Bureau’s 1999 request to OMB for approval of the forms for 

the ACS test programs stated that 

 27Posey, Welniak, and Nelson, p. 14. 

28Posey, Welniak, and Nelson, p. 15. 

29Charles Nelson and Kathleen Short, “The Distributional Implications of Geographic 

Adjustment of Poverty Thresholds,” U.S. Census Bureau, Housing and Household 

Economics and Statistics Division, Washington, D.C., December 2003. 

Evaluations of ACS, 

Long-Form, and CPS 

Data Comparisons 
Appendix V: Current Status of Unresolved 

Issues 

Page 77 GAO-05-82 American Community Survey 

“to make a transition from the Census 2000 long form to collecting long-form data 

throughout the decade, we will begin ACS data collection in 1,203 counties. This data 

collection will allow for comparison of estimates from Census 2000 with estimates from the 

ACS for all states, large cities, and population subgroups, and will help data users and the 

Census Bureau understand the differences between estimates from the ACS and the 

Census 2000 long form.”30

In testimony to the Congress a year later, Kenneth Prewitt, the Census 

Bureau’s Director, referred to the ongoing ACS test programs: 

“These data will also contribute to a comparison with data from Census 2000 that is 

necessary because there are differences in methods and definitions between the census 

and the ACS. Moreover, decision makers will want to compare an area’s data to those from 

Census 2000. Comparisons using data from the operational test and from the 31 sites are 

essential to determine how much measured change between Census 2000 and future years 

of the ACS is real and how much is due to operational differences between the ACS and the 

census.”31

When the Census Bureau began in 2001 to report on full implementation of 

the ACS, its first report focused on the operational feasibility of 

conducting the ACS.32 Its second report in 2002 focused on differences in 

operational characteristics of the ACS and the census long form, such as 

response rates and the extent of imputations.33

The 2002 report stated that three reports evaluating differences between 

the ACS and census long form would be published at the end of 2003.34 The 

Census Bureau repeated this schedule in March 2003 when it released 

 3064 Fed. Reg. 64 48759-48760 (Sept. 8, 1999). The Census Bureau made similar statements 

about the importance of comparisons in its request to OMB to extend approval of the 

supplementary survey forms in 67 Fed. Reg. 67 21629 (May 1, 2002). 

31Kenneth Prewitt, Director, U.S. Bureau of the Census, before the U.S. House of 

Representatives, Committee on Government Reform, Subcommittee on the Census, 

Summary of House Hearing on ACS July 20, 2000, The American Community Survey: A 

Replacement for the Census Long Form? Serial 106-246 (Washington, D.C.: July 20, 2000). 

32U.S. Census Bureau, Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey, Report 1, Demonstrating Operational Feasibility. 

33U.S. Census Bureau, Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey, Report 2, Demonstrating Survey Quality. 

34U.S. Census Bureau, American Community Survey Development Report Series Program 

Plan, an internal report prepared a month later, had called for completing one of these 

reports by the end of 2002. 
Appendix V: Current Status of Unresolved 

Issues 

Page 78 GAO-05-82 American Community Survey 

another official report on ACS plans.35 In September, we were told by one 

of the ACS experts that consultants had been hired to conduct evaluations 

for 4 of the 31 test sites. The reports on comparisons with long-form items 

and for the test sites were published in May, June, and July 2004. 

The results of these comparisons are similar to comparisons and 

evaluations of long-form data items previously prepared by Census Bureau 

staff, BLS, and GAO. 

In September 2002, we prepared national and state comparisons between 

the 2000 ACS supplementary survey and the 2000 Decennial Census long 

form for about 10 items and between the 2000 ACS supplementary survey 

and the 2000 CPS for the poverty and unemployment rates. From the longform comparisons, we reported that 

“These comparisons showed large national differences for key items that did not appear to 

be accounted for by coverage differences between the two surveys. For example, at the 

national level, the largest differences were for these items: (1) for the number of housing 

units lacking complete plumbing facilities, with the long-form estimate 27 percent higher 

than the estimate from the supplementary survey, and (2) for the number of unpaid family 

workers, with the long-form estimate 59 percent lower. . . . We also found a great degree of 

variation in the state differences between the long form and the supplementary survey.”36

From the CPS comparisons, we reported that 

“We found that at the national and state levels, there were small differences for the 

unemployment rate and for the poverty rate for all individuals. In contrast, comparisons of 

these rates for the CPS with these two surveys showed larger differences. The national 

unemployment rate, according to the CPS, was 4.0 percent, compared with 5.8 percent for 

the long form and 5.4 percent for the supplementary survey. The national rate for 

individuals in poverty for the CPS was 11.3 percent, compared with 12.4 percent for the 

long form and 12.5 percent for the supplementary survey.”37

Given these results, we recommended that the Census Bureau expand the 

scope of evaluation studies to develop supplementary survey estimates for 

states and large places consistent with the 2000 long form and that it 

 35U.S. Census Bureau, American Community Survey Operations Plan, Release 1. 

36GAO-02-956R, p. 11. 

37GAO-02-956R, p. 12. 
Appendix V: Current Status of Unresolved 

Issues 

Page 79 GAO-05-82 American Community Survey 

include in its evaluations comparisons of year-to-year changes for 

2001 and 2002, using data from the supplementary surveys and the CPS at 

the national and state levels for key economic and housing items. 

In September 2003, BLS received a report from a consultant who had been 

hired to evaluate differences between labor force data, such as the 

unemployment rate, reported in the ACS test programs and the CPS.38 The 

evaluation’s purpose was to provide BLS with information on whether and 

how to incorporate ACS data into its measures of unemployment and the 

labor force. The consultant compared several labor market indicators 

from the CPS and ACS for 2000–02 at the national and state levels: 

“Relative to the CPS, the ACS consistently generates lower estimates of the labor force and 

employment but higher estimates of unemployment. These patterns are present in each of 

the years 2000, 2001, and 2002. They are repeated in nearly all state-level data as well.”39

He made a series of recommendations for additional research, some 

requiring additional information from the Census Bureau. 

The need for such research was also reported in a January 2004 Census 

Bureau report that examined differences between labor force data from 

the CPS and the 2000 Decennial Census long form.40 Other findings and 

recommendations for further research similar to ours and those of BLS 

were also reported in research papers Census Bureau staff presented at 

the 2003 Joint Statistical Meetings. One paper on comparisons of income 

data for 2000 from the 2000 Decennial Census long form and the 2000 ACS 

Supplementary Survey reported that it 

“provided a summary of the major differences between the two income data sources, in 

terms of data collection, capture, and processing, and provided very preliminary 

assessments of the possible role these differences may have played.”41

The authors reported that additional work was needed to understand the 

differences and offered recommendations for further research. 

 38Wayne Vroman, Comparing Labor Market Indicators from the CPS and ACS 

(Washington, D.C.: Urban Institute, September 2003). 

39Vroman, p. 23. 

40Schneider.

41Posey, Welniak, and Nelson, “Income in the American Community Survey,” p. 14. 
Appendix V: Current Status of Unresolved 

Issues 

Page 80 GAO-05-82 American Community Survey 

Another paper presented at the same meetings examined differences 

between the national estimates for people aged 5 or older with a 

disability—48.9 million was the 2000 Census long-form estimate, 

39.7 million the C2SS estimate. The author did not determine which 

estimate was more reliable but did find that the wording of some questions 

might explain the overall difference. In addition, the author reported that 

more work, such as additional analysis of currently available data and 

testing of new questions, was needed to clearly identify the reasons for the 

difference.42 The differences in disability data were also the subject of a 

National Council on Disability position paper, which recommended 

changes to the questions on disability.43

In addition to results from these comparison studies, the NAS Panel on 

Research on Future Census Methods found in July 2003 that the Census 

Bureau needed to complete evaluations of differences between 

2000 Census long-form data and data from the ACS test sites and the 

2000–02 Supplementary Surveys. Specifically, the panel stated that 

“The Census Bureau should carry out more research to understand the differences between 

and relative quality of ACS estimates and long-form estimates, with particular attention to 

measurement error and error from nonresponse and imputation. The Census Bureau must 

work on ways to effectively communicate and articulate those findings to interested 

stakeholders, particularly potential end users of the data.”44

The panel also stated that, to facilitate this effort, 

“The Census Bureau should make ACS data available (protecting confidentiality) to 

analysts in the 31 ACS test sites to facilitate the comparison of ACS and census long-form 

estimates as a means of assessing the quality of ACS data as a replacement for census longform data. Again, with appropriate safeguards, the Census Bureau should release ACS data 

to the broader research community for evaluation purposes.”45

 42Stern, “Counting People with Disabilities.” 

43Lex Frieden, Chair, National Council on Disability, “Improving Federal Disability Data,” 

Washington, D.C., January 8, 2004. National Council on Disability, Newsroom, Publications, 

2004, http://www.ncd.gov/newsroom/publications/2004/publications.htm (May 11, 2004). 

44Cork, Cohen, and King, p. 99. 

45Cork, Cohen, and King, p. 99. 
Appendix V: Current Status of Unresolved 

Issues 

Page 81 GAO-05-82 American Community Survey 

One of the major differences between the ACS and the long form it will 

replace is that the ACS will provide data for geographic areas with 

populations smaller than 65,000 in terms of multiyear averages. Because of 

the statistical properties of these averages and users’ unfamiliarity with 

them, we and many other stakeholders have identified these averages as a 

major challenge for users, including federal agencies. The Census Bureau 

has recognized the need for such guidance on the averages but has not 

made public plans for the topics to be discussed or when the guidance will 

be published. 

From the 1998 conference that the Census Bureau had asked Westat to 

conduct on the quality of ACS data for rural data users, the report’s 

authors concluded that “On the basis of the full exchange between the 

Bureau and the participants, they saw no evidence of an antirural bias in 

the design of the ACS.”46 Nevertheless, they also concluded that the Census 

Bureau needed to conduct and expand its contacts with stakeholders and 

to conduct additional research on several issues we discussed in our 

report, including population controls, operational aspects of nonresponse 

followup, and multiyear averages. For these averages, the conference 

report noted that there would be issues with small geographic areas and 

the interpretation of changes in these averages: 

“In discussing this issue, a number of the participants thought that averages were 

particularly problematic for those areas in which change is irregular. For example, the 

question was raised as to the meaning of ‘average poverty’ over a 5-year period in which 

poverty rose and fell from one year to the next and, thus, the average would have no 

obvious meaning.”47

The report made similar comments with regard to such characteristics as 

unemployment and income. Although the conference participants had 

generally agreed with these concerns, the report pointed out that annually 

updating the 5-year averages “will provide some insight into trends, 

although turning points will be difficult to discern precisely, as will shortterm trends.”48

 46Graham Kalton and others, The American Community Survey: The Quality of Rural 

Data, A Report of a Conference (Rockville, Md.: Westat, June 29, 1998), p. 3. 

47Kalton and others, p. 12. 

48Kalton and others, p. 13. 

Information on Key 

Properties of 

Multiyear Averages 
Appendix V: Current Status of Unresolved 

Issues 

Page 82 GAO-05-82 American Community Survey 

About a year later, the Census Bureau had Westat convene another 

conference, this one focusing on the use of multiyear averages. The 

1999 report concluded: 

“Although a 5-year moving average will generally provide reasonably reliable cross-section 

statistics for all areas, including very small communities, some care will have to be 

exercised in choosing time periods for which changes in population or their characteristics 

are measured. With 5-year averages, four-fifths of the data in a pair of neighboring years 

will be identical. The change being measured will then be one-fifth of the difference 

between the most recent year and the first year of the earlier time period. The sampling 

errors of the differences will thus be based on annual sample sizes, not 5-year averages, 

and will generally be too large to make useful inferences for small areas. The two 5-year 

averages that are being compared should generally be discrete and non-overlapping 

periods, e.g., 2003–2007 and 2008–2012. These comparisons will have about the same 

reliability as changes between two censuses using data collected in the Census long 

form.”49

Census Bureau staff have been well aware of the difficulties of using the 

new multiyear averages. The Census Bureau’s Charles Alexander 

presented a paper at a 2001 Statistics Canada conference on statistical 

methodology in which he recognized that the multiplicity of estimates for 

the same geographic area would be an issue for users (and for the 

Bureau). He said that the Census Bureau’s presentation would 

“encourage analysts to use the same length of cumulation when comparing areas of 

different sizes . . . . For example, we would use one year for comparing states, but would 

recommend 5 years for all the counties in a table comparing large and small counties.”50

Alexander noted that this approach differed from that of Kish, the 

developer of the concept of a “rolling sample,” who would “let us use 

tables of counties with one-year estimates for large counties, 3-year 

averages for medium-sized ones, and 5-year averages for small ones.” He 

concluded this section of the paper by saying, “It will be interesting to see 

what practices data users will adopt in this regard.”51

 49Westat Inc., The American Community Survey: A Report on the Use of Multi-Year 

Averages (Rockville, Md.: April 30, 1999), p. 12. 

50Alexander, p. 6. 

51Alexander, p. 6. 
Appendix V: Current Status of Unresolved 

Issues 

Page 83 GAO-05-82 American Community Survey 

At the fall 2002 Census Advisory Committee Meetings, Navarro presented 

a paper that Alexander had written. Focusing primarily on the quality of 

the 5-year averages, the paper noted advantages and shortcomings, 

including that multiyear averages are not useful in all situations. For 

example, 

“If there is little change in the population over the time covered by the average, the 

interpretation is about the same as that of a point-in-time estimate with the advantage that 

the ACS estimate is more current than the historical decennial census long-form 

estimate.”52

The paper provided examples with “naive” assumptions about how users 

extrapolate between censuses to show that multiyear averages “work.” By 

implication, under other conditions, users will need guidance on when 

multiyear averages can be used. The paper also did not discuss the 

interpretation of changes in the multiyear averages, as in the 1999 Westat 

conference report or multiple estimates, which Alexander had discussed 

in his paper for the 2001 Statistics Canada conference. 

In September 2002, two reports focused on issues related to the statistical 

properties of multiyear averages. We published a report on several aspects 

of the ACS, including the selection of questions and the feasibility of 

conducting the ACS as a voluntary survey, and HUD released a report 

prepared for its staff on the use of the ACS for HUD programs.53

We stated in our report that the Census Bureau evaluation would not 

discuss “measures of stability of annual ACS data and ACS multiyear 

averages.” We recommended that, as a first step, the Census Bureau 

“Analyze and report on differences between year-to-year changes for 2001 and 2002, using 

the data—from ACS special supplements and the CPS at the national and state levels—for 

key economic and housing characteristics, such as the unemployment and poverty rates, to 

determine the stability of the annual ACS data.”54

 52Charles Alexander, “A Discussion of the Quality of Estimates from the American 

Community Survey for Small Population Groups,” written August 26, 2002, for the Census 

Advisory Committee of Professional Associations meeting, Washington, D.C., October 2–3, 

2002, p. 3. 

53GAO-02-956R and ORC Macro.

54GAO-02-956R, p. 25. 
Appendix V: Current Status of Unresolved 

Issues 

Page 84 GAO-05-82 American Community Survey 

We also discussed the need for additional information on the 

characteristics of the multiyear averages to help federal agencies make the 

transition to the ACS. We specifically noted the need for information on 

the selection of ACS data for geographic areas with populations larger 

than 20,000 for which there will be multiple estimates. On this issue, we 

stated that, “In addition, we found that the ACS development program did 

not cover information about different ways to integrate the annual data for 

states and large counties and the 3- and 5-year averages for smaller 

counties.”55

For example, federal agencies that need state data can choose to use the 

annual data, multiyear averages of the annual data, or 3-year or 5-year ACS 

averages. Federal agencies that also need county data can choose to use 

the most recent annual data for large counties and adjust the averages of 

the smaller counties to agree with annual data. Alternatively, they can 

choose to use various combinations of multiyear averages. As many 

federal agencies, as well as state and local governments, will be using the 

ACS data for allocating funds, Census Bureau guidance would reduce the 

inconsistent use of the multiple estimates. 

HUD is a major user of Decennial Census long-form data for various 

program applications. Its contract with ORC Macro to review how the ACS 

will affect HUD programs that previously relied on the Decennial Census 

long form for geographic area data resulted in a report that made two 

points about the multiyear averages, in addition to raising the previously 

discussed issues on the inflation adjustment to income. One of these 

issues related to interpretations of changes in the multiyear averages and 

their stability; the other related to the availability of multiple estimates for 

the same area. 

The ORC Macro report noted that year-to-year stability is important and 

needs to be addressed. It warned that the “differences in the precision of 

estimates or year-to-year changes in estimates can create problems for 

HUD applications.”56 The report used eligibility and level of benefits as an 

example of what could vary because of the effect of sampling variability 

on these changes. ORC Macro also stated: “The ACS will report data using 

different reporting periods for different sized areas. Inconsistent or 

 55GAO-02-956R, p. 15. 

56ORC Macro, p. vi. 
Appendix V: Current Status of Unresolved 

Issues 

Page 85 GAO-05-82 American Community Survey 

multiple reporting periods can create problems for HUD applications.”57

ACS data for many geographic areas will be available in terms of annual 

estimates and 3- and 5-year averages, and the annual and 3-year averages 

(for larger areas) will be available before estimates for smaller areas. As a 

result, HUD will have to choose from multiple measures for some 

geographic areas. The study noted that HUD might decide to (1) continue 

to use 2000 long-form data until 2008, when the first 5-year average data 

will be available for all levels of geography, or (2) use the most recently 

available data in all cases.58

ORC Macro’s report also expressed concern about the amount of annual 

ACS data that the Census Bureau will release for areas with populations 

smaller than 65,000, whose accuracy the Census Bureau has found does 

not meet publication standards. According to the study, the Census 

Bureau informed HUD that beginning in 2008, it would provide researchers 

and planners a “research file” containing annual ACS data for areas of all 

sizes, including census tracts. ORC Macro recommended that if the Census 

Bureau does release these data, HUD consider using these “unofficial” 

research file results in some of its applications. The study noted, however, 

that if HUD decided to use these unofficial data but other agencies decided 

not to use them, there would be no standardization across government 

programs in funding allocation where the same ACS items were used. 

The most recent request for the Census Bureau to provide users with 

guidance on using multiyear averages came in the July 2003 report by the 

NAS Panel on Research on Future Census Methods. The panel stated that 

“The Census Bureau should issue a user’s guide that details the statistical 

implications of the difference between point-in-time and moving average 

estimates for various uses.”59 In the report’s executive summary, the panel 

stated that “The Census Bureau must do significant work in informing data 

users and stakeholders of the features and the problems of working with 

moving average-based estimates.”60 It also expressed particular concern 

about the use of the multiyear (moving) averages in fund allocation 

formulas, noting that a multiyear average 

 57ORC Macro, p. vi. 

58Since ORC Macro’s study was issued, full implementation of the ACS has been delayed; 

the first 5-year averages will not be available until 2010. 

59Cork, Cohen, and King, pp. 99–100. 

60Cork, Cohen, and King, p. 6. 
Appendix V: Current Status of Unresolved 

Issues 

Page 86 GAO-05-82 American Community Survey 

“is a smoothed estimate; by averaging a particular time period’s data observation with 

those within a particular time window, the resulting estimate is meant to follow the general 

trend of the series but not be as extreme as any of the individual points. The ramifications 

of this basic concept emerge when moving average estimates are entered into sensitive 

allocation formulas or compared against strict eligibility cutoffs. A smoothed estimate may 

mask or smooth over an individual year drop in level of need, thus keeping the locality 

eligible for benefits; conversely, it may also mask individual-year spikes in activity and thus 

disqualify an area from benefits. It is clear that the use of smoothed estimates is neither 

uniformly advantageous nor disadvantageous to a locality; what is not clear is how often 

major discrepancies may occur in practice.”61

On another issue with multiyear averages, the panel noted, as the Westat 

report had done, the issue of interpreting year-to-year changes, stating, 

“It is incorrect to use annual estimates based on moving averages over several years when 

assessing change since some of the data are from overlapping time periods and hence 

identical. At the least, the results will yield incorrect estimates of the variance of the 

estimates of change. Therefore, users should be cautioned about this aspect of the use of 

moving averages.”62

During the past decade’s development of the ACS, the Census Bureau has 

had many opportunities to consult with and take account of input from 

stakeholders and users in making key decision on the programs. It has 

(1) sponsored NAS panels, (2) held user conferences, (3) hired consultants 

to organize two conferences, (4) met regularly with its advisory 

committees and other user groups, and (5) encouraged its staff to present 

reports at ASA meetings and meetings of similar professional 

organizations. In the past several years, we and other federal agencies 

have reported on the ACS and provided recommendations to the Census 

Bureau. It established the ACS Federal Agency Information Program in 

2003, responding to a recommendation we had made.63 It also announced 

 61Cork, Cohen, and King, p. 86. 

62Cork, Cohen, and King, p. 87. 

63GAO-02-956R, pp. 25–26. Information on the Federal Agency Information Program is at 

Census Bureau, American Community Survey, http://www.census.gov/acs/www (May 11, 

2004). 

External Consultation 
Appendix V: Current Status of Unresolved 

Issues 

Page 87 GAO-05-82 American Community Survey 

last year that it was looking into establishing a partnership with the 

Congress and its oversight entities.64

Despite these opportunities, many stakeholders have observed that these 

consultations have not been successful. NAS noted the Census Bureau’s 

lack of response to recommendations in last year’s report on the 

2010 Census. The Panel on Research on Future Census methods offered 

the following comment by referring to a 1995 NAS report: 

“Eight years later, faced with the task of offering advice on making the vision of continuous 

measurement a reality in the 2010 census, the similarity between the arguments then and 

now is uncanny. Similar, too, are the points of concern; the current panel is hard-pressed to 

improve upon the basic summary of concerns outlined by our predecessors. We are, 

however, much more sanguine that a compelling case can be made for the ACS and that it 

is a viable long-form replacement in the 2010 census.”65

The Census Bureau has neither responded to the panel’s first interim 

report in 2000 nor indicated that the recommendations were being 

adopted. The Census Bureau also has not responded to recommendations 

and issues raised by HUD and BLS. For example, it has not responded to 

HUD’s recommendations on the ACS adjustments to dollar-denominated 

items or to BLS’s recommendations on the ACS labor force questions. (On 

the issue of dollar-denominated items, we found no indication that the 

Census Bureau had ever consulted outside experts about either the 

methodology or the implementation.) 

Census Bureau summaries of discussion about the ACS at its Advisory 

Committee meetings from October 2000 to April 2003 also indicate a lack 

of responsiveness.66 During this period, committee members raised 

concerns about the ACS. In particular, they made recommendations about 

many of the issues we have discussed in this report, including the 

evaluations of ACS and long-form comparisons, the new residence rules, 

independent controls, ICPE, group quarters, and Spanish-language 

questionnaires. At the April 2003 meeting, ASA committee members also 

requested a change in the structure of the Advisory Committee meetings, 

 64Census Bureau, American Community Survey Operations Plan, Release 1, p. 56. 

65Cork, Cohen, and King, p. 98. 

66The record of committee recommendations for the October 2003 meetings was not 

available. 
Appendix V: Current Status of Unresolved 

Issues 

Page 88 GAO-05-82 American Community Survey 

asking the Census Bureau to spend less time on update sessions and more 

time on sessions devoted to gathering more detailed input, commentary, 

and recommendations on topics the Census Bureau needs and wants 

advice on. Although the Census Bureau has addressed issues related to 

ICPE and Spanish-language questionnaires, the meeting summaries do not 

report that it followed recommendations in other areas. 
Appendix VI: Comments from the Department 

of Commerce 

Page 89 GAO-05-82 American Community Survey 

Appendix VI: Comments from the 

Department of Commerce 
Appendix VI: Comments from the Department 

of Commerce 

Page 90 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 91 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 92 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 93 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 94 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 95 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 96 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 97 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 98 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 99 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 100 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 101 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 102 GAO-05-82 American Community Survey 
Appendix VI: Comments from the Department 

of Commerce 

Page 103 GAO-05-82 American Community Survey 
Appendix VII: GAO Contacts and Staff 

Acknowledgments 

Page 104 GAO-05-82 American Community Survey 

Robert P. Parker (202) 512-9750, parkerr@gao.gov. 

Christopher Moriarity (202) 512-5420, moriarityc@gao.gov 

Additional staff who made major contributions to this report were 

Heather Von Behren, Penny Pickett, Mitchell Karpman, Michael Volpe, 

Andrea Levine, Patricia Dalton, and Robert Goldenkoff. 

Appendix VII: GAO Contacts and Staff 

Acknowledgments 

GAO Contacts 

Staff 

Acknowledgments 
Bibliography 

Page 105 GAO-05-82 American Community Survey 

The first section in this bibliography lists documents on the history of the 

long form and mid-decade census. The remaining works are divided 

between numerous types of Census Bureau reports and papers, 

Association of Public Data Users papers, congressional hearings and 

testimony, and other reports and papers. Recent reports from the National 

Academy of Sciences are discussed in appendix II. Related GAO Products 

are listed in a separate section at the end of this report. 

Alexander, Charles H. “Still Rolling: Leslie Kish’s ‘Rolling Samples’ and the 

American Community Survey.” In Proceedings of Statistics Canada 

Symposium 2001: October 16–19. Ottawa: Statistics Canada, 2002. 

Anderson, Margo J., ed. Encyclopedia of the U.S. Census. Washington, 

D.C.: CQ Press, 2000. 

House of Representatives, Committee on Post Office and Civil Service, 

Subcommittee on Census and Population. Review of Major Alternatives 

for the Census in the Year 2000. Serial 102-25. Washington, D.C.: August 

1, 1991. 

House of Representatives, Committee on Post Office and Civil Service. 

Census Confidentiality/Mid-Decade Sample Survey Bill. Report 93-246. 

Washington, D.C.: June 4, 1973. 

House of Representatives, Committee on Post Office and Civil Service. 

Mid-Decade Censuses of Population, Unemployment, and Housing.

Report 780. Washington, D.C.: August 12, 1965. 

Salvo, Joseph, and Arun Peter Lobo. The American Community Survey: 

Quality of Response by Mode of Data Collection in the Bronx Test Site. 

Presented at 2002 Joint Statistical Meetings, New York City, August 14, 

2002. 

American Community Survey Operations Plan, Release 1. Washington, 

D.C.: March 2003. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 1. Demonstrating Operational 

Feasibility. Washington, D.C.: July 2001. 

Bibliography 

History of the Long 

Form and Mid-Decade 

Census 

Census Bureau ACS 

Reports 
Bibliography 

Page 106 GAO-05-82 American Community Survey 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 2. Demonstrating Survey Quality. 

Washington, D.C.: May 2002. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 3. Testing the Use of Voluntary 

Methods. Washington, D.C.: December 2003. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 4. Comparing General 

Demographic and Housing Characteristics With Census 2000. Washington, 

D.C.: May 2004. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 5. Comparing Economic 

Characteristics With Census 2000. Washington, D.C.: May 2004. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 6. The 2001-2002 Operational 

Feasibility Report of the American Community Survey. Washington, D.C.: 

May 2004. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 7. Comparing Quality Measures: 

The American Community Survey's Three-Year Averages and Census 

2000's Long Form Sample Estimates. Washington, D.C.: June 2004. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 8. Comparison of the American 

Community Survey Three-Year Averages and the Census Sample for a 

Sample of Counties and Tracts. Washington, D.C.: June 2004. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 9. Comparing Social 

Characteristics With Census 2000. Washington, D.C.: June 2004. 

Meeting 21st Century Demographic Data Needs: Implementing the 

American Community Survey. Report 10. Comparing Housing 

Characteristics With Census 2000. Washington, D.C.: July 2004. 
Bibliography 

Page 107 GAO-05-82 American Community Survey 

The presentations in this section were made by the Census Bureau’s 

Decennial Census Advisory Committee, Professional Association Advisory 

committees, and Race and Ethnic Advisory Committees. 

The ACS: Data Products to Meet User Needs. Race and Ethnic Advisory 

Committee meeting, Washington, D.C., March 14, 2001. 

Alexander, Charles, Alfredo Navarro, and Deborah Griffin. Update on ACS 

Evaluations. Decennial Census Advisory Committee meeting, Washington, 

D.C., November 5, 2001. 

Gordon, Nancy. The American Community Survey. Joint Meeting of the 

Census Bureau Advisory Committees, Washington, D.C., July 28, 2000. 

Gordon, Nancy. The American Community Survey. Decennial Census 

Advisory Committee meeting, Washington, D.C., September 21–22, 2000. 

Gordon, Nancy. The American Community Survey. Race and Ethnic 

Advisory Committees meeting, Washington, D.C., November 2, 2000. 

Gordon, Nancy. American Community Survey Update. Decennial Census 

Advisory Committee meeting, Washington, D.C., May 2, 2002. 

Griffin, Deborah. An Overview of the Research and Evaluation Program 

for the American Community Survey. Decennial Census Advisory 

Committee meeting, Alexandria, Virginia, October 2–4, 2002. 

Griffin, Deborah H. Comparing Characteristics from the American 

Community Survey and Census 2000: Methodology. Census Advisory 

Committee of Professional Associations meeting, Washington, D.C., April 

10–11, 2003. 

Navarro, Alfredo. American Community Survey: Use of Population 

Estimates as Controls in the ACS Weighting. Census Advisory Committee 

of Professional Associations meeting, Washington, D.C., October 23, 2003. 

Navarro, Alfredo. A Discussion of the Quality of Estimates from the 

American Community Survey for Small Population Groups. Census 

Advisory Committee of Professional Associations meeting, Washington, 

D.C., October 2–3, 2002. 

Weidman, Lynn, and Signe Wetrogan. Enhancing the Intercensal 

Population Estimates Program with ACS Data: Summary of Research 

Census Bureau 

Advisory Committee 

Presentations 
Bibliography 

Page 108 GAO-05-82 American Community Survey 

Projects. Census Advisory Committee of Professional Associations 

meeting, Washington, D.C., October 23, 2003. 

The memorandums listed here from the 20 in the Continuous 

Measurement series are those most directly related to topics we review in 

this report. 

Alexander, Charles H. A Continuous Measurement Alternative for the 

U.S. Census. CM-10, October 28, 1993. CM-11 summarized this paper at the 

1993 annual meeting of the American Statistical Association, San 

Francisco, California, August 10, 1993. 

Alexander, Charles H. Further Exploration of Issues Raised at the 

CNSTAT Requirements Panel Meeting. CM-13. Internal Census Bureau 

memorandum, Washington, D.C., January 31, 1994. 

Alexander, Charles H. A Prototype Continuous Measurement System for 

the U.S. Census of Population and Housing. CM-17. Presented at the 

annual meeting of the Population Association of America, Miami, Florida, 

May 5, 1994. 

Alexander, Charles H. Some Ideas for Integrating the Continuous 

Measurement System into the Nation’s System of Household Surveys.

CM-19A. Internal Census Bureau memorandum, Washington, D.C., January 

6, 1995. 

2004 Census Test Operational Plan. Washington, D.C.: September 29, 

2003. 

2010 Census Decision Memorandum Series No. 5, Finalizing Content for 

the 100 Percent Items in the 2010 Census and the American Community 

Survey. Washington, D.C.: June 3, 2004. 

2010 Census Planning Memorandum Series No. 24, Action Plan: 2010 

Research and Development Planning Group on Race and Ethnic Data 

Collection, Tabulation, and Editing. Washington, D.C.: June 9, 2004. 

2010 Census Planning Memorandum Series No. 26, Action Plan: 2010 

Research and Development Planning Group on Special Places/Group 

Quarters Development and Testing. Washington, D.C.: March 8, 2004. 

Census Bureau 

Continuous 

Measurement Series 

Census Bureau 

Internal Reports 
Bibliography 

Page 109 GAO-05-82 American Community Survey 

ACS-2010 Consistency Review Plan. Washington, D.C.: October 1, 2003. 

American Community Survey Development Report Series Program Plan. 

Washington, D.C.: rev. June 12, 2002. 

Abramson, Florence. Special Place/Group Quarters Enumeration. Census 

2000 Testing, Experimentation, and Evaluation Program, Topic Report 

No. 5. U.S. Census Bureau, Washington, D.C., February 2004. 

Adlakha, Arjun, J. Gregory Robinson, Kirsten West, and Antonio Bruce. 

Assessment of Consistency of Census Data with Demographic 

Benchmarks at the Subnational Level. Census 2000 Evaluation O.20. U.S. 

Census Bureau, Washington, D.C., August 18, 2003. 

Clarke, Sandra, John Iceland, Thomas Palumbo, Kirby Posey, and Mai 

Weismantle. Comparing Employment, Income, and Poverty: Census 

2000 and the Current Population Survey. Census 2000 Auxiliary 

Evaluation. U.S. Census Bureau, Washington, D.C., September 2003. 

Palumbo, Thomas and Paul Siegel. Accuracy of Data for Employment 

Status as Measured by the CPS-Census 2000 Match. Census 2000 

Evaluation B.7. U.S. Census Bureau, Washington, D.C., May 4, 2004. 

Schneider, Paula. Content and Data Quality in Census 2000. Census 

2000 Testing, Experimentation, and Evaluation Program, Topic Report No. 

12. U.S. Census Bureau, Washington, D.C., January 22, 2004. 

Bureau staff presented many ACS-related papers at the August 2003 Joint 

Statistical Meetings in San Francisco, California. We reviewed the papers 

in this section in detail because they were related to comparisons between 

ACS estimates and 2000 Census results. 

Boggess, Scott, and Nikki L. Graf. Measuring Education: A Comparison 

of the Decennial Census and the American Community Survey. 

Presented at Joint Statistical Meetings, San Francisco, California, August 

7, 2003. 

Dye, Jane Lawler. Grandparents Living with and Providing Care for 

Grandchildren: A Comparison of Data from Census 2000 and 2000 

American Community Survey. Presented at Joint Statistical Meetings, 

San Francisco, California, August 7, 2003. 

Census 2000 

Evaluation Reports 

Census Bureau 2003 

JSM Staff Papers 
Bibliography 

Page 110 GAO-05-82 American Community Survey 

Love, Susan, and Deborah Griffin. A Closer Look at the Quality of Small 

Area Estimates from the American Community Survey. Presented at 

Joint Statistical Meetings, San Francisco, California, August 4, 2003. 

Posey, Kirby G., Edward Welniak, and Charles Nelson. Income in the 

American Community Survey: Comparisons to Census 2000. Presented 

at Joint Statistical Meetings, San Francisco, California, August 7, 2003. 

Raglin, David A., Theresa F. Leslie, and Deborah H. Griffin. Comparing 

Social Characteristics between Census 2000 and the American 

Community Survey. Presented at Joint Statistical Meetings, San 

Francisco, California, August 3, 2003. 

Stern, Sharon M. Counting People with Disabilities: How Survey 

Methodology Influences Estimates in Census 2000 and the Census 2000 

Supplementary Survey. Presented at Joint Statistical Meetings, San 

Francisco, California, August 7, 2003. 

Alexander, Charles H. American Community Survey Data for Economic 

Analysis (October 2001). Presented at the Census Advisory Committee of 

the American Economic Association meeting, Washington, D.C., October 

18–19, 2001. 

Alexander, Charles H. Recent Developments in the American Community 

Survey. Presented at the 1998 Joint Statistical Meetings, Dallas, Texas, 

August 12, 1998. 

Alexander, Charles H., Sharon Brown, and Hugh Knox. American 

Community Survey Data for Economic Analysis (December 2001).

Presented at the Federal Economic Statistics Advisory Committee 

meeting, Washington, D.C., December 14, 2001. 

Alexander, Charles H., Scot Dahl, and Lynn Weidman. Making Estimates 

from the American Community Survey. Presented at the 1997 Joint 

Statistical Meetings, Anaheim, California, August 13, 1997. 

Alexander, Charles H., and Signe Wetrogan. Integrating the American 

Community Survey and the Intercensal Demographic Estimates 

Program. Presented at the 2000 Joint Statistical Meetings, Indianapolis, 

Indiana, August 14, 2000. 

Other Census Bureau 

Staff Research Papers 
Bibliography 

Page 111 GAO-05-82 American Community Survey 

Butani, Shail, Charles Alexander, and James Esposito. Using the 

American Community Survey to Enhance the Current Population 

Survey: Opportunities and Issues. Presented at the 1999 Federal 

Committee on Statistical Methodology Research Conference, Arlington, 

Virginia, November 15-17, 1999. 

Davis, Mary Ellen, and Charles H. Alexander, Jr. The American 

Community Survey: The Census Bureau's Plan to Provide Timely 21st 

Century Data. Missouri Library World, Spring 1997. 

DeMaio, Theresa J., and Kristen A. Hughes. Report of Cognitive Research 

on the Residence Rules and Seasonality Questions on the American 

Community Survey. U.S. Bureau of the Census, Statistical Research 

Division, Washington, D.C., July 2003. 

Love, Susan, Donald Dalzell, and Charles Alexander. Constructing a 

Major Survey: Operational Plans and Issues For Continuous 

Measurement. Presented at the 1995 Joint Statistical Meetings, Orlando, 

Florida, August 16, 1995. 

Nelson, Charles, and Kathleen Short. The Distributional Implications of 

Geographic Adjustment of Poverty Thresholds. U.S. Bureau of the Census, 

Housing and Household Economics Statistics Division, Washington, D.C., 

December 2003. 

Posey, Kirby G., and Edward Welniak. Income in the ACS: Comparisons 

to the 1990 Census. Presented at the American Community Survey 

Symposium, Suitland, Maryland, March 1998. 

Salvo, Joseph, and Arun Peter Lobo. The American Community Survey: 

Quality of Response by Mode of Data Collection in the Bronx Test Site.

Presented at the 2002 Joint Statistical Meetings, New York, August 14, 

2002. 

Smith, Amy Symens. The American Community Survey and Intercensal 

Population Estimates: Where Are the Crossroads? Technical Working 

Paper 31, U.S. Census Bureau, Population Division, Washington, D.C., 

December 1998. 

Davis, Mary Ellen. The American Community Survey Data Products,

Alexandria, Virginia, October 20, 2003. Association of Public 

Data Users Papers 
Bibliography 

Page 112 GAO-05-82 American Community Survey 

Gage, Linda, State of California, Department of Finance. American 

Community Survey: Research by the Data User Community. Alexandria, 

Va.: October 20, 2003. 

Petroni, Rita. How Do 3-Year Averages from the ACS Compare to Census 

2000 Data? (Preliminary Results). Alexandria, Va.: October 20, 2003. 

Salvo, Joseph, City of New York, Planning Department. American 

Community Survey: Research by the Data User Community. Alexandria, 

Va.: October 20, 2003. 

Scarr, Harry A. Deputy Director, Census Bureau. Continuous 

Measurement. Association of Public Data Users, Washington, D.C.; 

October 16, 1994. 

Barron, William Jr., Acting Director, U.S. Bureau of the Census, before the 

U.S. House of Representatives, Committee on Government Reform, 

Subcommittee on the Census. The Census Bureau’s Proposed American 

Community Survey (ACS), Serial 107-9. Washington, D.C.: June 13, 2001. 

Kincannon, Charles Louis, Director, U.S. Bureau of the Census, before the 

U.S. House of Representatives, Subcommittee on Technology, Information 

Policy, Intergovernmental Relations, and the Census. The American 

Community Survey: The Challenges of Eliminating the Long Form from 

the 2010 Census, Serial 108-97. Washington, D.C.: May 13, 2003. 

Prewitt, Kenneth, Director, U.S. Bureau of the Census, before the U.S. 

House of Representatives, Committee on Government Reform, 

Subcommittee on the Census. House Hearing on ACS July 20, 2000. The 

American Community Survey: A Replacement for the Census Long 

Form? Serial 106-246. Washington, D.C.: July 20, 2000. 

Kalton, Graham, and others. The American Community Survey: The 

Quality of Rural Data, Report of a Conference. Rockville, Md.: Westat, 

June 29, 1998. 

Nardone, Thomas, and others. Examining the Discrepancy in 

Employment Growth between the CPS and the CES. Washington, D.C.: 

FESAC, October 17, 2003. 

Congressional 

Hearings and 

Testimony 

Other Reports and 

Papers 
Bibliography 

Page 113 GAO-05-82 American Community Survey 

National Council on Disability. Improving Federal Disability Data. 

Washington, D.C.: January 9, 2004. 

ORC Macro. The American Community Survey: Challenges and 

Opportunities for HUD. Calverton, Md.: September 27, 2002. 

Vroman, Wayne. Comparing Labor Market Indicators from the CPS and 

ACS. Washington, D.C.: Urban Institute, September 2003. 

Westat Inc. The American Community Survey: A Report on the Use of 

Multi-Year Averages. Rockville, Md.: April 30, 1999. 
Related GAO Products 

Page 114 GAO-05-82 American Community Survey 

2010 Census: Cost and Design Issues Need to Be Addressed Soon. 

GAO-04-37. Washington, D.C.: January 15, 2004. 

Medicaid Formula: Differences in Funding Ability among States Often 

Are Widened. GAO-03-620. Washington, D.C.: July 10, 2003. 

Formula Grants: 2000 Census Redistributes Federal Funding Among 

States. GAO-03-178. Washington, D.C.: February 24, 2003. 

Major Management Challenges and Program Risks: Department of 

Commerce. GAO-03-97. Washington, D.C.: January 1, 2003. 

The American Community Survey: Accuracy and Timeliness Issues.

GAO-02-956R. Washington, D.C.: September 30, 2002. 

Legal Authority for American Community Survey. B-289852. 

Washington, D.C.: April 4, 2002. 

Medicaid Formula: Effects of Proposed Formula on Federal Shares of 

State Spending. GAO/HEHS-99-29R. Washington, D.C.: February 19, 1999. 

Decennial Census: Overview of Historical Census Issues. 

GAO/GGD-98-103. Washington, D.C.: May 1, 1998. 

Poverty Measurement: Adjusting for Geographic Cost-of-Living 

Difference. GAO/GGD-95-64. Washington, D.C.: March 9, 1995. 

Status of the Statistical Community after Sustaining Budget 

Reductions. GAO/IMTEC-84-17. Washington, D.C.: July 18, 1984. 

Related GAO Products 

(460557) 
The Government Accountability Office, the audit, evaluation and 

investigative arm of Congress, exists to support Congress in meeting its 

constitutional responsibilities and to help improve the performance and 

accountability of the federal government for the American people. GAO 

examines the use of public funds; evaluates federal programs and policies; 

and provides analyses, recommendations, and other assistance to help 

Congress make informed oversight, policy, and funding decisions. GAO’s 

commitment to good government is reflected in its core values of 

accountability, integrity, and reliability. 

The fastest and easiest way to obtain copies of GAO documents at no cost 

is through GAO’s Web site (www.gao.gov). Each weekday, GAO posts 

newly released reports, testimony, and correspondence on its Web site. To 

have e-mail you a list of newly posted products every afternoon, go to 

www.gao.gov and select “Subscribe to Updates.” 

The first copy of each printed report is free. Additional copies are $2 each. 

A check or money order should be made out to the Superintendent of 

Documents. GAO also accepts VISA and Mastercard. Orders for 100 or 

more copies mailed to a single address are discounted 25 percent. Orders 

should be sent to: 

U.S. Government Accountability Office 

441 G Street NW, Room LM 

Washington, D.C. 20548 

To order by Phone: Voice: (202) 512-6000 

TDD: (202) 512-2537 

Fax: (202) 512-6061 

Contact: 

Web site: www.gao.gov/fraudnet/fraudnet.htm 

E-mail: fraudnet@gao.gov

Automated answering system: (800) 424-5454 or (202) 512-7470 

Gloria Jarmon, Managing Director, JarmonG@gao.gov (202) 512-4400 

U.S. Government Accountability Office, 441 G Street NW, Room 7149 

Washington, D.C. 20548 

Jeff Nelligan, Managing Director, NelliganJ@gao.gov (202) 512-4800 

U.S. Government Accountability Office, 441 G Street NW, Room 7149 

Washington, D.C. 20548 

GAO’s Mission 

Obtaining Copies of 

GAO Reports and 

Testimony 

Order by Mail or Phone 

To Report Fraud, 

Waste, and Abuse in 

Federal Programs 

Congressional 

Relations 

Public Affairs