2010 Census: Follow-up Should Reduce Coverage Errors, but Effects on Demographic Groups Need to Be Determined
Published: 2010-12-14T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: The U.S. Census Bureau (Bureau) puts forth tremendous effort to conduct a complete and accurate count of the nation's population and housing; yet some degree of error in the form of persons missed, duplicated, or counted in the wrong place is inevitable due to the complexity in counting a large and diverse population. The Bureau designed two operations, Coverage Follow-up (CFU) and Field Verification (FV), to reduce certain types of counting, or coverage, errors in the 2010 Census. GAO was asked to assess (1) the extent to which the Bureau completed CFU and FV on schedule and within estimated cost and (2) the implications of their key design elements for improving coverage. GAO reviewed Bureau evaluations, planning, and other documents on CFU and FV, and prior GAO work, and interviewed Bureau officials.
section_title: What GAO Found
paragraphs: The Bureau completed CFU and FV on schedule and within budget. FV cost $21 million (about 38 percent less than estimated) and CFU cost about $267 million (about 2 percent less than estimated). These operations followed up on potential errors on census returns or lists of addresses after census data had been initially collected. Their completion provided follow-up data used by subsequent data processing that removed errors from the official census tabulations. Three of the Bureau's key CFU design elements will likely improve overall census accuracy, but their effect on undercounts of different demographic groups is not clear. One key design element increased the number and types of follow-up cases. The Bureau expanded the scope of CFU from about 2 million households in the 2000 Census to more than 7 million in 2010. It also added 20 different types of households for potential follow-up. New types included households that reported members temporarily residing elsewhere, such as at college, in nursing homes, or in jail. According to the Bureau, the 2010 CFU operation should remove more than 2.7 million coverage errors from the census. Another key design element of CFU prioritized follow-up cases based on their likelihood to result in a census correction, which was a reasonable attempt to leverage the resources for the operation. However, the Bureau's evaluation plans, based on considerations of what may best reduce cost or increase accuracy in the future, do not link the demographic characteristics of households to how they responded to the additional questions or CFU results for those households. Therefore, it is unclear whether the prioritized follow-up will help reduce differences in the accuracy of census counts across demographic groups. Finally, CFU's design relied on a telephone-only approach to complete follow-up rather than personal visits. This limited costs, resulting in more follow-up and likely more coverage errors being removed from the census. But the telephone-only decision excluded about 700,000 households from CFU that could not be contacted by telephone. Prior Bureau experience indicates that some historically undercounted groups were less likely to be reachable by telephone, and more recent independent research suggests that trends in telecommunication usage may also make it harder to reach some demographic groups this way in the future. Yet the Bureau's evaluation plans do not include an assessment of either the usefulness of the telephone numbers it collected in reaching specific groups or the effect of these trends. Greater understanding of how best to reach different groups as well as the influence of trends on the effectiveness of CFU could help to control costs while working to further reduce differential undercounts.
section_title: What GAO Recommends
paragraphs: GAO recommends that the Secretary of Commerce direct the Bureau to assess (1) how well questions to help identify miscounted people on census forms helped reduce differences in the undercounts between demographic groups; (2) the degree to which telephone numbers led to completed contacts for households of various demographic characteristics; and (3) how trends in telecommunication usage and new technology may influence the effectiveness of CFU. The Secretary of Commerce concurred with our recommendations.

section_title: Letter
paragraphs: The U.S. Census Bureau (Bureau) puts forth tremendous effort to conduct  a complete and accurate count of the nation’s population and housing;  nonetheless, some degree of error in the form of persons missed,  duplicated, or counted in the wrong place during the decennial census is  inevitable due to the complexity of counting a large and diverse  population. errors identified after households provided their census responses. During  CFU, a contractor telephoned certain households in an attempt to  determine if someone had been miscounted, such as when the number of  people reported living in a household did not match the number of people  whose name and demographic information was included on the  household’s census form. During FV, the Bureau visited addresses that had  been provided by persons that thought they had been missed by the  census and that did not match the Bureau’s master address list. From the  2000 Census, the Bureau expanded CFU and allocated more than $200  million in additional funds—including $30 million provided by the  American Recovery and Reinvestment Act of 2009—which allowed the  Bureau to include an additional 1.1 million households within the scope of  CFU.
After reviewing the status of CFU in 2008, we recommended that the  Bureau submit its plans for CFU to Congress and decide how it would  conduct the operation. The Bureau did so and completed CFU in August  2010 and FV in September 2010. As requested, for this review we examined  (1) the extent to which FV and CFU were completed on schedule and  within cost estimates, and (2) key design elements of CFU and FV, the  implications for those design elements on improving coverage, and  possible lessons learned to the extent similar efforts are used in the 2020  Census. This report is one of three we are releasing today. The other  reports focus on the Bureau’s efforts to reach out to and enumerate hard- to-count populations, and efforts to complete other key census-taking  activities. Both reports identify preliminary lessons learned, as well as  potential focus areas for improvement.
To meet both objectives, we assessed Bureau planning, testing, and  schedule documents and interviewed Bureau officials to supplement and  verify the currency and relevance of documentation obtained. For the first  objective we also assessed the performance of CFU and FV against the  cost, timeliness, and other metrics the Bureau used to monitor the  operations. Additionally, for the second objective we reviewed our past  reports and Bureau literature on known limitations of follow-up methods  to identify key design elements and their implications. We also assessed  Bureau study and evaluation plans. We conducted this performance audit  from March 2010 to December 2010 in accordance with generally accepted  government auditing standards. Those standards require that we plan and  perform the audit to obtain sufficient, appropriate evidence to provide a  reasonable basis for our findings and conclusions based on our audit  objectives. We believe that the evidence obtained provides a reasonable  basis for our findings and conclusions based on our audit objectives.
subsections: section_title: Background
paragraphs: To help ensure a complete count, the Bureau had a number of operations  aimed at capturing census data from people and households that  otherwise might have been missed by the census. For example, the Be  Counted program was designed to make special census questionnaires  available to those who may not have received one, including people who  do not have a usual residence, such as transients, migrants, and seasonal  farm workers. The questionnaires were placed in over 38,000 locations  across the country, including libraries, convenience stores, and other  places people might frequent. The Bureau conducted FV to verify the  existence of new addresses provided on these questionnaires and through  other sources that were not already on the Bureau’s master address list.  The procedures enumerators followed to verify addresses in 2010 were  largely similar to those used in the 2000 Census. In 2000, the Bureau  visited nearly 900,000 addresses as part of its FV operation, verifying the  addition of over 450,000 addresses to its address list.
To help ensure accuracy in the population count in 2000, the Bureau used  telephone interviews in another operation to follow up with two types of  household responses: households too large to include all their members on  the form and households with apparent discrepancies on their  questionnaires, such as when the number of people reported in the  household population box does not match the number of people whose  name and demographic information is included on the form. The Bureau  placed calls to these households to determine if additional persons might  have been missed (undercounted), if persons might have been counted in  error (overcounted), or if persons might have been counted in the wrong  place (possibly an overcount in one place and an undercount in another).  The Bureau followed up on over 2.5 million households at a cost of  approximately $67 million, resulting in over 152,000 people being added to  the official census count and approximately 258,000 others being removed.
In response to Census 2000 experiences and in order to help achieve a  Bureau goal of reducing differential undercounts, the Bureau added  questions to the 2010 Census questionnaire to better identify potential  coverage problems. These additional questions—called coverage probes— were to help identify households that may have omitted (undercounted)  persons, due to familial relationships such as young children and extended  family residing in the household but not reported on the census  questionnaire due to space limitations, or households that may have  counted persons more than once (overcounted), due to situations where  members spent time elsewhere, such as relatives living in nursing homes  or college dormitories. The resulting coverage probes used on the 2010  Census questionnaire are shown below in figure 1.
section_title: The Bureau Completed FV and CFU on Schedule and within Budget, but Needs to Improve the Accuracy of Its Cost Estimates
subsections: section_title: FV Was Completed on Schedule and Well Under Budget
paragraphs: The 2010 FV operation began July 21, 15 days early, and finished on  schedule on September 8, 2010. During that time, the Bureau visited nearly  456,000 addresses. The Bureau’s preliminary results show that about 49  percent of those addresses were verified as valid housing units, 33 percent  did not exist, and 18 percent were duplicates. The Bureau expects to  report the final results in its formal evaluations of FV, planned for release  in July 2011.
Completing FV on schedule was commendable, given that the Bureau had  to make several late changes to the design of the operation as part of a  contingency plan. Before beginning the FV operation, the information  technology (IT) system the Bureau had expected to use to support the  operation experienced testing and development delays. Furthermore, the  Bureau was experiencing difficulty with this system being used to support  other major census field operations. Therefore the Bureau developed and  implemented a contingency plan, which substituted a modified version of  the IT system used to support the 2010 Census Coverage Measurement  operations and the IT system used for the 2000 Census, changed some  related procedures for shipping workload materials, and significantly  expanded the quality-assurance program to mitigate the risk of introducing  additional changes to the contingency IT system. The Bureau attributes its  ability to complete FV on time to its aggressive monitoring of the risk that  IT systems might not be ready, its having identified a contingency IT  system in advance, and the small scale of the FV operation compared to  other census field operations, which allowed for the rapid adoption of  alternative procedures. The Bureau’s timely response to IT system delays  demonstrates the benefits of the Bureau having developed risk mitigation  plans for significant risks, as we have recommended before.
The Bureau completed FV at a cost of $21 million, 38 percent lower than  the $33.8 million estimated for the operation. Bureau officials are still  researching why costs were lower than expected, but their preliminary  analysis attributes cost savings to increased productivity and reduced  operational inputs, such as training hours and mileage. The final cost of  the operation was unexpected considering that the Bureau estimated that  the late changes made by the contingency plan would increase the cost per  case and increase total costs by nearly $15 million for the estimated  workload. Under the Bureau’s original calculation, adding the contingency  plan raised the estimated cost-per-case to about $74, far more than the $53  per case assumed in the initial budget estimate or the $46 per case  reported at the end of the operation. The Bureau has not attempted to  separately identify how much of the final cost per case increase was  attributable to the contingency plan or other factors.
Achieving cost savings is a positive development. However, our prior work  has highlighted the need for the Bureau to develop more accurate and  rigorous cost estimates for census operations. A high-quality cost  estimate is the foundation of a good budget, providing an estimate of thefunding required to efficiently execute a program. Additionally, according to our Cost Assessment Guide, a cost estimate should be a “living”  document that is continually updated as actual costs begin to replace  original estimates, so that it remains relevant and current. previously recommended that the Bureau document where actual costs  differ from those estimated to help document lessons learned and th basis for changes made to assumptions used. The Bureau updated its cost  estimate for FV as its estimated workload changed and when it considered  adoption of the contingency plan. However, moving forward it will be  important to be able to explain the variation in its cos t estimates.
GAO, GAO Cost Estimating and Assessment Guide: Best Practices for Developing and  Managing Capital Program Costs, GAO-09-3SP (Washington, D.C.: March 2009).
section_title: CFU Was Completed on Schedule and Exceeded Performance Targets
paragraphs: The 2010 CFU operation began and finished on schedule, ensuring that  CFU data were available for subsequent data processing. From April 11 to  August 14, Bureau contractors telephoned nearly 7.4 million households,  of which 4.9 million (66 percent) were complete interviews, meeting their  estimated workload target. The Bureau expects to be able to report an  analysis of the effect of CFU on census coverage in the spring of 2011.
The Bureau completed CFU at an estimated cost of $267 million, about 2  percent less than the initial cost estimate for the operation. As shown in  table 1 below, the Bureau completed a slightly higher percentage of cases  it attempted and spent on average less time on the phone completing each  interview than expected.
Given mandated deadlines that the Bureau faces for delivering census  tabulations, completing field data collection including CFU and FV on  schedule was crucial for subsequent processing activities to proceed and  be completed on schedule.
section_title: CFU Should Help Improve Overall Census Coverage, but Its Effect on Different Demographic Groups May Not Be Uniform
paragraphs: Three design decisions for the 2010 CFU operation should improve overall  census accuracy. These decisions include  expanding the scope of the 2010 CFU operation compared to its 2000  operation,    prioritizing types of follow-up cases, and   contacting identified CFU households using only the telephone.
subsections: section_title: The Bureau’s Increase in the Number and Types of CFU Cases Should Improve Overall Census Accuracy
paragraphs: A key design decision the Bureau made for the 2010 CFU was to expand  the scope of its coverage follow-up operation from 2000 to follow up on  additional types of cases that it believed would help reduce the differential  undercount. While continuing to follow up on the two types of cases that  constituted the 2000 follow-up operation—large households and those  with apparent count discrepancies—the Bureau identified 20 additional  types of cases potentially to cover in 2010. One of these types of cases  came from the use of administrative records from other federal sources,  such as demographic information and addresses of families receiving  tenant subsidies from an information system at the Department of Housing  and Urban Development, to identify persons associated with a household’s  address who might have been omitted from the household’s census form.  Most of the additional types of cases were identified from responses to the  new coverage probes on the census questionnaire discussed earlier.  Additional types included households with responses indicating household  members present who may not have been recorded on the initial census  form, such as newborn babies, foster children, roommates or live-in  babysitters, or household members who may have lived or stayed at more  than one place, such as college students or nursing-home residents.
Expanding the scope of the 2010 CFU increased the number of cases the  Bureau followed up on from about 2.5 million cases in 2000 to about 8  million cases in 2010. According to the Bureau, the 2010 CFU operation  should result in more than 2.9 million coverage errors being removed from  the census, including overcounts and undercounts, compared to more than  400,000 coverage errors being removed in 2000. The more coverage errors  are removed from the official census count, the more the overall accuracy  of the census is improved.
section_title: The Effect of the Bureau’s Prioritization of Coverage Follow-up on Differential Undercounts Is Not Clear
paragraphs: A second key design decision the Bureau made for CFU was to prioritize  the types of cases it would follow up on, likely increasing the overall  number of coverage errors corrected but possibly affecting demographic  groups differently. The Bureau had to prioritize follow-up cases, since the  expansion of the CFU scope resulted in an estimated 22.5 million potential  CFU cases, far exceeding what its time and budget for the 2010 CFU  operation would permit. Bureau planning documents indicate that along  with the extra time needed to pursue 22.5 million cases, it would have cost  approximately $800 million more to complete all of the possible follow-up  cases.
In April 2010, the Bureau formally documented its decision to prioritize  follow-up based on cost and estimates of the number of corrections that  would result from each type of case, and documented which cases it  planned to include in follow-up. The Bureau estimated that in addition to  households with apparent discrepancies on their questionnaires and  households too large to include all their members on the form—the two  types of cases it focused on in 2000—it would complete follow-up on 8 of  20 additional types of cases. However, due to a combination of higher call  efficiency and lower-than-expected workloads for some of the selected  types of cases, in the end the Bureau was able to follow up on an  additional three types of CFU cases.
The Bureau’s decisions to expand the scope of CFU and prioritize the CFU  cases will likely result in a greater number of coverage errors being  removed from official census tabulations than were removed in 2000,  increasing CFU’s effectiveness in improving overall census accuracy in  2010. Prioritization of the CFU cases to contact was a reasonable attempt  to leverage the resources and time available for the operation. However,  because the specific coverage probes the Bureau used on census  questionnaires do not clearly map to specific demographic groups, the  extent to which the prioritized follow-up will help achieve the Bureau’s  goal of reducing the differential undercount is unclear. For example, one  of the Bureau’s priorities for follow-up was households indicating that  persons may have been included who should have been counted  elsewhere, such as persons in jail, in college, or in the military. Among the  types that the Bureau did not follow up on were households that reported  persons who were sometimes living elsewhere seasonally or as part of  custody-sharing arrangements. The demographic characteristics of the  people covered by each of these probes are not likely to be the same as the  general population. Thus, following up on one set of cases but not others  will likely have a different, though unknown, effect on particular  demographic groups.
The Bureau acknowledges that, in so far as households in certain groups  are not contacted by telephone but have coverage errors, there would  likely be a smaller improvement in coverage for those demographic  groups. Yet Bureau officials maintain that since it would be difficult to  design follow-up based directly on household characteristics such as race  and Hispanic origin, relying on situation- and relationship-based probes on  census questionnaires—such as the Bureau did in 2010—may be the most  effective way to identify coverage follow-up cases. To that end, the Bureau  has 2010 data on how each household responded to each coverage probe  and the demographics of each household, and will ultimately know which  probes led to corrections of census coverage errors. The Bureau plans to  report the demographic groups for which CFU identified corrections as  part of its formal assessment of CFU, but that assessment does not include  a link between the results for each probe and historically undercounted  groups. Bureau officials have explained that its evaluation choices are  driven by consideration of the best value to the decennial census in terms  of informing possible cost benefit analyses and improvements to accuracy,  and can change in response to new information the Bureau may obtain.  Linking these data from 2010 CFU could help the Bureau decide which of  the probes and priorities best helped the Bureau both improve overall  accuracy and reduce the differential undercount, and better inform the  Bureau decision making on the use of coverage probes for 2020.
section_title: The Effect of the Bureau’s Telephone-Only Approach on Differential Undercounts Is Not Clear
paragraphs: A third key design decision the Bureau made for CFU was to rely solely on  telephone interviews rather than use personal visits to contact households  during the 2010 CFU operation. For those households the Bureau can  reach by telephone, this decision should have enabled the Bureau to  reduce many more census errors, because it allowed the Bureau to follow  up with more households than it could have with personal visits using the  same level of funding. A Bureau evaluation of its 2000 coverage follow-up  activities suggested that personal visits be used for households for which  the Bureau has no valid telephone number, noting that traditionally  undercounted groups, such as renters and certain minority groups, were  less likely to have valid phone numbers. Yet personal visits are  significantly more expensive than telephone calls, costing about $71 per  case compared to about $19 per case for telephone calls, according to  Bureau results from a 2006 census test of CFU.
To increase the effectiveness of its telephone-only approach, the Bureau  implemented several specific recommendations from its evaluation of the  2000 follow-up operation, including the use of a commercial database to  assist with identifying the telephone numbers that were invalid or missing  for CFU cases. Bureau officials believe that adopting these  recommendations led to significant increases in the effectiveness of  telephone follow-up, with reported response rates to telephone calls  conducted as part of 2010 Census tests of 63 percent in 2004, 80 percent in  2005, and 78 percent in 2006. For 2010 CFU, Bureau management reporting  indicates that the response rate exceeded its target goal of 65 percent.
The Bureau’s decision to rely solely on telephone calls and related  measures to complete CFU resulted in lower cost and more effective  follow-up, and should contribute to a greater number of coverage errors  being removed from official census tabulations compared to 2000. While  these design decisions helped increase overall census accuracy, their  effect on the Bureau’s goal to reduce the differential undercount is less  clear. This is because the Bureau excluded from CFU any household for  which it did not obtain a useable telephone number. A useable phone  number was obtained either from the respondent’s return and could be a  wireless or landline telephone number or through a telephone number  look-up that resulted in the retrieval of landline numbers only. This is  potentially problematic for two reasons.
First, current research indicates that there are significant differences  between households that use only wireless telephones and those that have  landline telephones, with groups of households with high wireless-only  usage being part of historically undercounted populations. According to  our analysis of Bureau management reporting, the Bureau excluded about  700,000 households from follow-up because it lacked a usable contact  telephone number. The Bureau relied only on landline telephone numbers  from its commercial database, due to concerns about not knowing the  geographic location of wireless phones it might dial and the possible  financial burden on wireless customers from unsolicited calls. The Bureau  did not immediately know which household-provided numbers were  wireless, so it had rules concerning when calls could be made, to restrict  calls to local times appropriate for the location of addresses provided. The  Bureau has not attempted to track how many of the telephone numbers it  called or excluded from follow-up were wireless numbers, what types of  CFU cases they were for, or what the demographic characteristics of these  households might be. According to the Bureau, it has asked the contractor  that carried out the telephone calls for the Bureau to report the disposition  of cases where a number was found during look-up as part of the  contractor’s forthcoming assessment. Future Bureau decisions about how  to contact households for follow-up can be better informed if the Bureau  strengthens its understanding of how different sources of contact  information can affect its goal to reduce the differential undercount.
Furthermore, trends regarding the use of wireless telephones indicate that  some households within hard-to-count populations may be harder to  contact in the future using landline telephone operations. For example, a  recent Centers for Disease Control and Prevention study shows that  wireless-only households has more than doubled between January 2006  and December 2009 from about 11 percent to more than 24 percent of the  nation’s households. And in May 2010, the Pew Research Center found that  wireless-only adults pose a significant challenge to data collection by  telephone, because such adults are substantially different demographically  from those reached on a landline phone. According to the Pew Research  Center, wireless-only adults tend to be young, single, renters, and with  lower income. This research also found that minorities made up a larger  share of the wireless-only group with far more Hispanics, African- Americans, and people of other or mixed racial backgrounds than those  with landline telephones. Such trends could pose a challenge to possible  future Bureau reliance on telephone-based contacts intended to help  improve census coverage of such demographic groups to the extent they  do not provide their telephone numbers on census questionnaires. Broader  ongoing shifts in the use of other telecommunications, including a variety  of social media, may also influence the relative effectiveness of strategies  relying on telephone communication.
section_title: Conclusions
paragraphs: Overall, the Bureau generally implemented FV and CFU on schedule and  under budget, which is a noteworthy accomplishment given the inherent  challenges of conducting a cost-effective census. The Bureau also updated  its cost estimates for FV periodically as its estimated workload for FV  evolved, and adopted design changes for CFU that likely contributed  significantly to improving the overall accuracy of the census. At the same  time, the Bureau’s experience in implementing these two operations  highlights additional actions that may improve the Bureau’s understanding  of the effectiveness of CFU in reducing differential undercounts and help  improve planning for 2020 to the extent that the Bureau conducts such  operations as part of the next decennial.
First, our previous work has highlighted the importance of accurate and  rigorous cost estimates; thus, it will be important for the Bureau to assess  the factors that led to significant variance in cost estimates for FV.  Knowing this will allow the Bureau to develop more accurate cost  estimates in the future, and will help the Bureau focus on cost  containment as it prepares for the 2020 Census. We are not making  recommendations at this time regarding the Bureau’s cost estimation  methods, as we have already done so in a previous report. The Bureau  agreed with those recommendations at that time and has begun  implementing them.
Second, given the research and testing of coverage probes leading up to  their use in 2010, it will be important for the Bureau to assess the degree to  which the coverage probes helped address the differential undercount.  This will help the Bureau understand whether the probes the Bureau  prioritized for follow-up worked as intended and could help the Bureau  determine which probes or other follow-up procedures to use in the future  to improve census accuracy.
Third, it will be important for the Bureau to determine the effectiveness of  the phone numbers it obtained from census returns or its commercial  database in making contact with households of different follow-up and  demographic groups. The decision to rely solely on telephone calls and no  personal visits involved an implicit trade-off between the opportunity for  cost savings with improved overall census accuracy and an opportunity  possibly to help reduce historic differential undercounts. If the Bureau  better understood the demographic composition of those for whom it did  and did not obtain telephone numbers, and for whom it was and was not  successful in reaching by phone, it could better determine the effect of this  design decision on differential undercounts. Also, better knowledge of  how best to reach different groups could help identify effective sources of  contact information or strategies for using them for future censuses,  further helping to control costs while still working to address differential  undercounts.
Finally, whether it is a trend of households moving away from reliance on  landlines, or other possible emerging trends related to growth in other  modes of communication and new technology, the Bureau’s future design  decisions will benefit from tracking and assessing the implications of such  trends and leveraging or mitigating their effect where possible. For  example, under a scenario where the Bureau continues to rely on  telephones for contacting households, the Bureau might need to adopt  strategies for increasing the number of usable telephone numbers  provided by census respondents or revisit its specific rules concerning  when to dial numbers. Moving forward, it will be important for the Bureau  to identify how rapid changes in technology and the public’s use of them  may affect the effectiveness of its efforts to improve census accuracy, both  overall and in terms of reducing differential undercounts.
section_title: Recommendations for Executive Action
paragraphs: We recommend that the Secretary of Commerce require the Director of  the U.S. Census Bureau to take the following three actions to improve the  Bureau’s planning for the 2020 Census:    To help the Bureau decide which coverage probes, if any, to use and  prioritize for future follow-up efforts, assess the extent to which  historically overcounted and undercounted demographic groups  responded to the probes the Bureau followed up on and determine the  effectiveness of specific probes in reducing differential undercounts.
To support the Bureau’s efforts to control costs while improving  census accuracy, determine the demographic characteristics of the  households for which it did and did not obtain telephone numbers and,  to the extent feasible, assess the degree to which the telephone  numbers were usable and led to completed contacts for households of  various follow-up groups and demographic characteristics.
To ensure that the design of future follow-up efforts is effective in  improving census coverage, assess the implications that trends in  landline and wireless usage and other modes of communication and  new technology may have both on the design decisions for future CFU- like operations and on their effectiveness in improving census  coverage in terms of both overall census accuracy and differential  undercounts.
section_title: Agency Comments and Our Evaluation
paragraphs: The Secretary of Commerce provided written comments on a draft of this  report on December 1, 2010. The comments are reprinted in appendix I.  The Department of Commerce agreed with the overall findings and  recommendations and appreciated our efforts in helping the Bureau  develop a successful evaluation plan for the 2020 Census. The department  also included comments from the Bureau on certain statements in the  report.
The Bureau commented on our discussion of its initial estimate that the  contingency plan it adopted would increase the cost of FV. The Bureau  commented that its initial estimate that the contingency plan would  increase the cost of FV by $15 million was based on estimated workloads,  that the final FV workload was much smaller, and that it had not  attempted to reestimate the cost effect of the contingency plan separately.  We revised the text to more fully reflect that the estimated increase was  based on estimated workload, and emphasized the changes in “cost per  case,” which better reflects the effect on cost of changes in workload.
The Bureau also commented on our discussion of telecommunication  trends and the Bureau’s need to understand how different sources of  contact information can affect its goal to reduce the differential  undercount. The Bureau agreed that the trend toward wireless  communication needs more attention in the future and described how it  had not yet collected certain data that might be needed to carry out  evaluation of the type we recommended. According to our analyses, the  additional data are easily obtained. We revised the text to point more  specifically to the type of data that could help the Bureau with future  decisions about how to reach historically undercounted groups.
We are sending copies of this report to the Secretary of Commerce, the  Director of the U.S. Census Bureau, and interested congressional  committees. The report also is available at no charge on GAO’s Web site at  http://www.gao.gov.
If you have any questions about this report please contact me at (202) 512- 2757 or goldenkoffr@gao.gov. Contact points for our Offices of  Congressional Relations and Public Affairs may be found on the last page  of this report. Key contributors to this report were Ty Mitchell, Assistant  Director; Mark Abraham; Sara Daleksi; Ron Fecso; Andrea Levine; Donna  Miller; Jessica Thomsen; Jonathon Ticehurst; Holly Williams; and  Katherine Wulff.
section_title: Appendix I: Comments from the Department of Commerce
section_title: Related GAO Products
paragraphs: 2010 Census: Key Efforts to Include Hard-to-Count Populations Went  Generally as Planned; Improvements Could Make the Efforts More  Effective for Next Census. GAO-11-45. Washington, D.C.: December 14,  2010.  2010 Census: Data Collection Operations Were Generally Completed as  Planned, but Long-standing Challenges Suggest Need for Fundamental  Reforms. GAO-11-193. Washington, D.C.: December 14, 2010.  2010 Census: Census Bureau Continues to Make Progress in Mitigating  Risks to a Successful Enumeration, but Still Faces Various Challenges.  GAO-10-132T. Washington, D.C.: October 7, 2009.
GAO Cost Estimating and Assessment Guide: Best Practices for  Developing and Managing Capital Program Costs. GAO-09-3SP.  Washington, D.C.: March 2009.  2010 Census: The Bureau’s Plans for Reducing the Undercount Show  Promise, but Key Uncertainties Remain. GAO-08-1167T. Washington,  D.C.: September 23, 2008.  2010 Census: Census Bureau Should Take Action to Improve the  Credibility and Accuracy of Its Cost Estimate for the Decennial Census.  GAO-08-554. Washington, D.C.: June 16, 2008.  2010 Census: Bureau Needs to Specify How It Will Assess Coverage  Follow-up Techniques and When It Will Produce Coverage Measurement  Results. GAO-08-414. Washington, D.C.: April 15, 2008.
Information Technology: Census Bureau Needs to Improve Its Risk  Management of Decennial Systems. GAO-08-79. Washington, D.C.:  October 5, 2007.