2010 Census: Population Measures Are Important for Federal Funding Allocations
Published: 2007-10-29T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: The decennial census is a constitutionally-mandated activity that produces critical data used to apportion congressional seats, redraw congressional districts, and allocate billions of dollars in federal assistance. This testimony discusses (1) the various measures of population used to allocate federal grant funds (2) how the accuracy of the population count and measurement of accuracy have evolved and the U.S. Census Bureau's (Bureau) plan for coverage measurement in 2010; and (3) the potential impact that differences in population estimates can have on the allocation of grant funds. This testimony is based primarily on GAO's issued work in which it evaluated the sensitivity of grant formulas to population estimates.
section_title: What GAO Found
paragraphs: In fiscal year 2000, GAO found that 85 percent of federal government obligations in grants to state and local governments were distributed on the basis of formulas that use data such as state population and personal income. The decennial census is the foundation for measuring the nation's population. It provides a count of the population every 10 years, and is the starting point for estimates of population made in years between the censuses. Obtaining an accurate population count through the decennial census has been a concern since the first census in 1790. Concern that the decennial census undercounted the population has continued since then. To measure accuracy, the Bureau since 1940 has used demographic analysis, in which it compares census counts with information on births, deaths, and other information. With the exception of 1990, the Bureau's demographic analysis shows that the extent to which the census undercounted the population has declined. More recently, the Bureau has used statistical techniques in which it compares the census count with the results of an independent sample survey of the population. For 2010, the Bureau plans to use similar statistical techniques to measure the accuracy and coverage of the census. Evaluating the accuracy of the census is essential given the importance of the data, the need to know the nature of any errors, and the cost of the census overall. GAO's prior work has illustrated that the accuracy of state and local population estimates may have some effect on the allocation of grant funds. Specifically, to show the sensitivity of grant programs to alternative population estimates, GAO simulated how two grant program formulas would allocate federal funds to states if population estimates were substituted for census counts. This simulation was done for illustrative purposes only. While only actual census numbers should be used for official purposes, this simulation showed some shifting of grant funds among the states when estimates were used. For example, recalculating allocations of Social Services Block Grant funds using estimates of population for 2000, rather than the census count, would result in shifting $4.2 million--or 0.25 percent--of $1.7 billion in fiscal year 2004 funds. Specifically, 27 states and the District of Columbia would have gained $4.2 million and 23 states would have lost a total of $4.2 million.

section_title: Letter
paragraphs: Thank you for the opportunity to be here today to discuss the role that the  nation’s population count plays in the allocation of federal funds to states  and localities. My remarks today describe (1) the various measures of  population used to allocate federal grant funds (2) how the accuracy of the  census count and measurement of accuracy have evolved, and (3) the  potential impact that differences in the census count and population  estimates can have on the allocation of grant funds.
As you know, the decennial census is a critical national effort mandated by  the Constitution. Census data are used to apportion congressional seats,  redraw congressional districts, and allocate billions of dollars in federal  assistance to state and local governments. The census count also serves as  a foundation for annual estimates of the nation’s population. Along with  the decennial census count, these annual estimates directly and indirectly  affect the distribution of federal assistance to state and local governments.  The U.S. Census Bureau (Bureau) puts forth tremendous effort to conduct  an accurate count of the nation’s population. However, some degree of  error in the form of persons missed or counted more than once is  inevitable. Further, because of limitations in methods for annually  estimating the population during the years between censuses, the  difference between an annual estimate of the population on census day  and the census count itself can emerge. Because many federal grant  programs rely directly or indirectly on population measures, inaccuracies  in census counts and methodological problems with population estimates  can affect the allocation of funds.
My remarks are based primarily on reports we have previously issued. To  describe the various measures of population used to allocate federal grant  funds, we examined the logistics and data from postcensal population  estimates, the American Community Survey (ACS) and the Current  Population Survey. To obtain insight on how the accuracy of the  population count and the measurement of accuracy have evolved, we  reviewed information from the Census Bureau’s Decennial Statistical  Studies Division, as well as previous GAO reports. To describe the  potential impact that differences in population estimates can have on the  allocation of grant funds, we relied on work we reported to this  subcommittee last year, as well as prior work. We conducted our work in  accordance with generally accepted government auditing standards.
subsections: section_title: Population Measures Are Used in Grant Formulas
paragraphs: Decennial census data play a key role in the allocation of many grant  programs. In fiscal year 2004, the federal government administered 1,172  grant programs, with $460.2 billion in combined obligations. Most of these  obligations were concentrated in a small number of grants. For example,  Medicaid was the largest formula grant program, with federal obligations  of $183.2 billion, or nearly 40 percent of all grant obligations, in fiscal year  2004. Many of the formulas used to allocate grant funds rely upon  measures of population, often in combination with other factors. In  addition to the census count, the Bureau has programs that estimate more  current data on population and population characteristics that are derived  from the decennial census of population. Grant formula allocations also  use the estimated data from the Bureau’s postcensal population estimates,  the Current Population Survey, and the American Community Survey.
Because the decennial census provides population counts once every ten  years, the Bureau also estimates the population for the years between  censuses. These estimates are referred to as postcensal population  estimates. They start with the most recently available decennial census  data and for each year adjust population counts for births, deaths, and  migration. Because these population estimates are more current than the  decennial population counts, the distribution formulas for federal grants  often use these data. For example, the allocation formula for the Social  Services Block Grants uses the most recent postcensal population  estimates to distribute funds.
While the decennial census and postcensal estimates provide annual data,  the Current Population Survey provides monthly data. This survey’s  sampling design relies on information developed for the decennial census  and its data are revised annually to be consistent with the postcensal  estimates. The survey is primarily designed to generate detailed  information about the American labor force, such as the number of people  unemployed. Data from this survey are also used to allocate funds for  programs, for instance programs under the Workforce Investment Act.
Another survey, the American Community Survey (ACS), provides detailed  socioeconomic characteristics for the nation’s communities. The ACS  relies on information developed for the decennial census and its annual  data are controlled to be identical to postcensal population estimates.  Currently, the ACS provides information on communities with populations  over 65,000. Data from the ACS are also used to allocate federal funds,  such as determining fair market rent levels used in the Section 8 housing  voucher program. Because the ACS is to replace 2010 census long form  socioeconomic data, it is expected that ACS data will be used more  extensively in other federal assistance programs in the future. Beginning in  2010, 5-year estimates will be available for areas to the smallest block  groups, census tracts, small towns, and rural areas. Beyond their use by  the federal government, the population counts and estimates are also used  extensively by state and local governments, businesses, nonprofits, and  research institutions.
Population-based data drawn from the decennial census, postcensal  population estimates, and the ACS play critical roles in the conduct of  community development programs undertaken by the federal, state, and  local governments. Such data are central to the conduct of the federal  government’s Community Development Block Grant program (CDBG), the  federal government’s 13th largest formula grant program with $3 billion in  obligations in fiscal year 2004. Since 1974, this program has provided  $120 billion to help communities address a host of urban problems ranging  from poverty and deteriorating housing to population loss and social  isolation. Given the breadth of the program’s objectives and the diversity  of the nation’s communities, CDBG employs four formulas to allocate  funds among 50 states, the District of Columbia, and 1,080 local  governments. These formulas depend on census data, including total  population, individuals in poverty, lagging population growth, households  in overcrowded homes, as well as the number of pre-1940 homes.
section_title: Accuracy of Population Count Is Important
paragraphs: An accurate census relies on finding and counting people—only once—in  the right place and getting complete, correct information on them. Seeking  to obtain an accurate count has been a concern since the first census in  1790. Concern about undercounting the population continued through the  decades. In the 1940s, demographers began to obtain a more thorough  understanding of the scope and nature of the undercount. For example,  the selective service registration of October 1940 showed 2.8 percent more  men than the census count. According to the Bureau, operations and  programs designed to improve coverage have resulted in the total  undercount declining in all but one decade since the 1940s. These  measures of coverage are based on demographic analysis, which compares  the census count to birth and death certificates and other administrative  data (see fig. 1).
Modern coverage measurement began with the 1980 Census, when the  Bureau compared decennial figures to the results of an independent  sample survey of the population. In using statistical methods such as  these, the Bureau began to generate detailed measures of the differences  among undercounts of particular ethnic, racial and other groups. In 1990,  the Bureau relied on a Post-Enumeration Survey to verify the data it  collected through the 1990 Census. For this effort, the Bureau interviewed  a sample of households several months after the 1990 Census, and  compared the results to census questionnaires to determine if each  sampled person was correctly counted, missed, or double counted in the  Census. The Bureau estimated that the net undercount, which it defined as  those missed minus those double counted, came to about 4 million  people. To estimate the accuracy of the 2000 Census, the Bureau  conducted the Accuracy and Coverage Evaluation (A.C.E.), which was an  independent sample survey designed to estimate the number of people  that were over- and undercounted in the census, a problem the Bureau  refers to as coverage error. This evaluation found that in the 2000 Census  there was a net overcount. For 2010 the Bureau plans a census coverage  measurement program that will, among other things, produce estimates of  components of census net and gross coverage error (the latter includes  misses and erroneous enumerations) in order to assess accuracy.
section_title: Population Estimates May Affect Allocation of Federal Funds
paragraphs: The accuracy of state and local population estimates may have an effect,  though modest, on the allocation of grant funds among the states. In our  June 2006 report, we analyzed how sensitive two federal formula grants  are to alternative population estimates, such as those derived by statistical  methods. In the June 2006 report, we recalculated certain federal  assistance to the states using the A.C.E. population estimates from the  2000 Census, as well as the population estimates derived from the Post- Enumeration Survey, which was administered to evaluate the accuracy of  the 1990 Census. This simulation was done for illustrative purposes only— to demonstrate the sensitivity of government programs to alternative  population estimates. While only the actual census numbers should be  used for official purposes, our simulation shows the extent to which  alternative population counts would affect the distribution of selected  federal grant funds and can help inform congressional decision making on  the design of future censuses.
We selected the Social Services Block Grant (SSBG) as part of this  simulation because the formula for this block grant program, which is  based solely on population, and the resulting funding allocations are  particularly sensitive to alternative population estimates. At a given level  of appropriation, any changes in the state’s population relative to other  states’ changes would have a proportional impact on the allocation of  funds to the state. In fiscal year 2004, the federal government allocated  $1.7 billion to states in block grant funds under the program. Recalculating  these allocations using statistical population estimates from the 2000  A.C.E., only $4.2 million—or 0.25 percent—of $1.7 billion in block grant  funds would have shifted. The total $1.7 billion SSBG allocation would not  have changed because SSBG receives a fixed annual appropriation. In  other words, those states receiving additional funds would have reduced  the funds of other states.
In short, 27 states and the District of Columbia would have gained   $4.2 million and 23 states would have lost a total of $4.2 million. Based on  our simulation of the funding formula for this block grant program, the  largest percentage changes were for Washington, D.C., which would have  gained 2.05 percent (or $67,000) in grant funding and Minnesota which  would have lost 1.17 percent (or $344,000). For the programs we  examined, less than half of a percent of total funding would be  redistributed by using the revised population counts. Figure 2 shows how  much (as a percentage) and where SSBG funding in 2004 would have  shifted as a result of using statistical population estimates for recalculating  formula grant funding by state. We previously reported that using 1990  adjusted data as the basis for allocations had little relative effect on the  distribution of annual funding to states. More recently, we reported that  statistical population estimates from the 2000 Census would have shifted a  smaller percentage of funding compared to those from the 1990 Census  because the difference between the actual and estimated population  counts was smaller in 2000. For example, using statistical estimates of the  population following the 1990 Census, a total of 0.37 percent of SSBG  funds would have shifted among the states in fiscal year 1998.
In addition to any impact that inaccuracies in the census count may have  on allocation of federal funds, between decennials differences between  the actual population and population estimates could affect fund  allocation. To calculate grant amounts, formula grants generally rely on  annual population estimates for each state developed by the Bureau. State  populations are estimated by adding to the prior year’s population  estimate the number of births and immigrants and subtracting the number  of deaths and emigrants. These estimates are subject to error, mainly  because migration between states and between the United States and  other countries is difficult to measure. By the end of the decade, when the  census count is taken, a significant gap may have arisen between the  population estimate and the census count. We found that by the time of  the 2000 census count, the annual estimates of population differed from  the 2000 count by about 2.5 percent. This “error of closure” was  substantially larger than that for the 1990 census—0.6 percent. We found  that correcting population estimates to reflect the 2000 census count  redistributes among states about $380 million in federal grant funding for  Medicaid, Foster Care, Adoption Assistance, and SSBG. Most of the shift in  funding occurred in fiscal year 2003 when federal matching rates for three  of the programs were based on population estimates derived from the 2000  census. For the SSBG program, the shift occurred in 2002 when it began  using the 2000 census count.
Complete and accurate data from the decennial census are central to our  democratic system of government. These same data serve as a foundation  for the allocation of billions of dollars in federal funds to states and local  governments. Because of the importance of the once-a-decade count, it is  essential to ensure that it is accurate. Though the overall undercount has  generally declined since it has been measured, evaluating the accuracy of  the census continues to be essential given the importance of the data, the  need to know the nature of any errors, and the cost of the census overall.  We continue to monitor the Bureau’s progress in this important effort.
Mr. Chairman, this concludes my remarks. I will be glad to answer any  questions that you, Mr. Turner, or other subcommittee members may have.
section_title: Contacts and Acknowledgments
paragraphs: For further information regarding this statement, please contact Mathew  Scire, Director, Strategic Issues, on (202) 512-6806 or at sciremj@gao.gov.  Contact points for our Offices of Congressional Relations and Public  Affairs may be found on the last page of this testimony. Individuals making  key contributions to this statement included Steven Lozano, Assistant  Director; Betty Clark; Robert Dinkelmeyer; Greg Dybalski; Ron Fecso;  Sonya Phillips; Michael Springer; and Cheri Truett.
section_title: Related GAO Products
paragraphs: Federal Assistance: Illustrative Simulations of Using Statistical  Population Estimates for Reallocating Certain Federal Funding. GAO- 06-567. Washington, D.C.: June 22, 2006.
Data Quality: Improvements to Count Correction Efforts Could Produce  More Accurate Census Data. GAO-05-463. Washington, D.C.: June 20, 2005.
Census 2000: Design Choices Contributed to Inaccuracy of Coverage  Evaluation Estimates. GAO-05-71. Washington, D.C.: November 12, 2004.  2010 Census: Cost and Design Issues Need to Be Addressed Soon. GAO- 04-37. Washington, D.C.: January 15, 2004.
Formula Grants: 2000 Census Redistributes Federal Funding Among  States. GAO-03-178. Washington, D.C.: February 24, 2003.  2000 Census: Coverage Measurement Programs’ Results, Costs, and  Lessons Learned. GAO-03-287. Washington, D.C.: January 29, 2003.  2000 Census: Complete Costs of Coverage Evaluation Programs Are Not  Available. GAO-03-41. Washington, D.C.: October 31, 2002.
The American Community Survey: Accuracy and Timeliness Issues.  GAO-02-956R. Washington, D.C.: September 30, 2002.  2000 Census: Refinements to Full Count Review Program Could Improve  Future Data Quality. GAO-02-562. Washington, D.C.: July 3, 2002.  2000 Census: Coverage Evaluation Matching Implemented as Planned,  but Census Bureau Should Evaluate Lessons Learned. GAO-02-297.  Washington, D.C.: March 14, 2002.
Formula Grants: Effects of Adjusted Population Counts on Federal  Funding to States. GAO/HEHS-99-69. Washington, D.C.: February 26, 1999.
Formula Programs: Adjusted Census Data Would Redistribute Small  Percentage of Funds to States. GAO/GGD-92-12. Washington, D.C.:  November 7, 1991.
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