2010 Census:

Efforts to Build an Accurate Address List Are Making Progress, but Face Software and Other Challenges

GAO-10-140T: Published: Oct 21, 2009. Publicly Released: Oct 21, 2009.

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Robert N. Goldenkoff
(202) 512-2757


Office of Public Affairs
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The decennial census is a constitutionally mandated activity that produces data used to apportion congressional seats, redraw congressional districts, and help allocate billions of dollars in federal assistance. A complete and accurate master address file (MAF), along with precise maps--the U.S. Census Bureau's (Bureau) mapping system is called Topologically Integrated Geographic Encoding and Referencing (TIGER)--are the building blocks of a successful census. If the Bureau's address list and maps are inaccurate, people can be missed, counted more than once, or included in the wrong location. This testimony discusses the Bureau's readiness for the 2010 Census and covers: (1) the Bureau's progress in building an accurate address list; and (2) an update of the Bureau's information technology (IT) system used to extract information from its MAF/TIGER? database. Our review included observations at 20 early opening local census offices in hard-to-count areas. The testimony is based on previously issued and ongoing work.

The Bureau has taken, and continues to take measures to build an accurate MAF and to update its maps. From an operational perspective, the Local Update of Census Addresses (LUCA) and address canvassing generally proceeded as planned, and GAO did not observe any significant flaws or operational setbacks. Group quarters validation got underway in late September as planned. A group quarters is a place where people live or stay that is normally owned or managed by an entity or organization providing housing and/or services for the residents (such as a boarding school, correctional facility, health care facility, military quarters, residence hall, or dormitory). LUCA made use of local knowledge to enhance MAF accuracy. Between November 2007 and March 2008, over 8,000 state, local, and tribal governments participated in the program. However, LUCA submissions generated a relatively small percentage of additions to the MAF. For example, of approximately 36 million possible additions to the MAF that localities submitted, 2.4 million (7 percent) were not already in the MAF. The other submissions were duplicate addresses, non-existent, or non-residential. Address canvassing (an operation where temporary workers go door to door to verify and update address data) finished ahead of schedule, but was over budget. Based on initial Bureau data, the preliminary figure on the actual cost of address canvassing is $88 million higher than the original estimate of $356 million, an overrun of 25 percent. The testing and improvements the Bureau made to the reliability of the hand held computers prior to the start of address canvassing played a key role in the pace of the operation, but other factors were important as well, including the prompt resolution of technical problems and lower than expected employee turnover. The Bureau's address list at the start of address canvassing consisted of 141.8 million housing units. Listers added around 17 million addresses and marked about 21 million for deletion. All told, listers identified about 4.5 million duplicate addresses, 1.2 million nonresidential addresses, and about 690,000 addresses that were uninhabitable structures. The overall quality of the address file will not be known until later in the census when the Bureau completes various assessments. While the Bureau has made some improvements to its management of MAF/TIGER? IT such as finalizing five of eight test plans, GAO continues to be concerned about the lack of finalized test plans, incomplete metrics to gauge progress, and an aggressive testing and implementation schedule going forward. Given the importance of MAF/TIGER? to an accurate census, it is critical that the Bureau ensure this system is thoroughly tested.

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