Because of rising costs, a fundamental reexamination of how the Bureau conducts the decennial census—including improving the cost- effectiveness of the actual count, or enumeration—is needed. In response to external pressures to contain costs, including our 2010 report calling for such a reexamination, the Bureau is researching and testing innovations and improvements (as necessary) in an effort to conduct the 2020 Census at a lower cost per housing unit than the cost estimate of the 2010 Census, while still maintaining high quality. (The 2010 Census cost estimate was approximately $94 per housing unit, in constant 2010 dollars.) Census costs have risen over the years: the cost of the 2010 Census represents a 38 percent increase in the cost per housing unit over costs for the 2000 Census; this in turn was a 76 percent increase over 1990 Census costs. According to Bureau officials, without substantial and bold innovation, the cost of conducting the 2020 Census likely will continue this trend, and may become prohibitive. (Figure 1 illustrates the increase in cost per housing unit from 1970 through 2010.) According to the Bureau’s 2020 Census Business Plan, the rising costs of the 2010 Census were largely driven by several factors, including substantial investments in a major national update of its address list during 2009, just prior to the enumeration in 2010. The address list— referred to by the Bureau as its Master Address File (MAF)—is a data file that contains a list of all known living quarters in the United States and Puerto Rico. Since 2000, the Bureau has used addresses provided by the U.S. Postal Service (USPS) Delivery Sequence File (DSF) as a starting point to update the MAF. The Bureau uses the MAF to support the decennial census as well as the American Community Survey and other ongoing demographic surveys.maintains its Topologically Integrated Geographic Encoding and Referencing system (TIGER): this system contains spatial geographical information that associates MAF address data with TIGER geography data on the Bureau’s maps. In conjunction with the MAF, the Bureau To determine whether and how to reengineer address canvassing for the 2020 Census, the Bureau is conducting ongoing efforts to improve its map and address databases. For example, the Bureau’s Geography Division is working with USPS, other federal agencies, and state, local, and tribal governments on a new program called the Geographic Support System Initiative (GSS-I). This initiative allows government agencies at all levels to regularly share and continuously update their address lists and road data with the Bureau. According to Bureau documents, GSS-I is relying on partnering with federal, state, tribal, and local government entities—as well as the private sector—to meet two Census-related data needs: obtaining accurate, complete, and timely information about where people live (such as address data), coordinates of residential structures, and other map features (such as street centerlines), and detecting information changes, so that the Bureau can identify such things as new roads and structures and update the MAF/TIGER database in response. According to the Bureau’s current plans, state, local, and tribal governments (which maintain address lists for purposes such as emergency response and property assessment) would have the opportunity to share addresses with the Bureau throughout the decade, rather than only during the 2 years prior to the census, as was done for the 2010 Census. One of the Bureau’s efforts to improve its address and mapping database involves two projects within the Bureau’s 2020 Research and Testing Program. These projects are using modeling to predict where changes (e.g., address additions and deletions) are likely to occur in the MAF. These models may be used to identify areas where update activities are required to assure the MAF is as complete and accurate as possible. If the Bureau decides to limit its address canvassing, this information is intended to help determine which areas meet acceptable quality thresholds for address coverage, as well as to identify areas in which address canvassing would be more effective in assuring a complete and accurate address list. In another, related effort—also integrated with the 2020 Research and Testing Program—the Bureau’s Geography Division has a team in place to interactively review address and mapping information (including imagery and other source materials) in order to identify areas in which counts of addresses in the MAF are consistent with numbers of housing units on the ground, as well as to identify areas in need of updating. Bureau officials said that they are planning to test the modeling projects in 2014 and 2015, and to compare them to the interactive review effort, in order to establish evidence of what mix of modeling and imagery-based reviews might best identify areas most in need of updating. Details on how the comparison will be made and tested are not yet available for our review. Additionally, in a test beginning in September 2014, the Bureau will conduct a Partial Block Canvassing Test—a component of their larger Address Validation Test. For this test, Census staff will canvass in areas even smaller than the usual blocks of geography used for canvassing, according to Bureau officials. This is being done under the belief that if the Bureau can demonstrate operational success at canvassing such small areas—what it refers to as “partial block canvassing”—it may be able to reengineer its canvassing operation by targeting efforts to similarly small areas. Doing so would eliminate the expense of canvassing an entire geographic block when only a part of it is in need of update. In another effort, the Bureau is investigating the role and possible contributions the private sector can make in improving its address and mapping databases. According to Bureau officials, reliance on the private sector is necessary in order to maintain the major upgrades that were made to its address and mapping databases for the last decennial. As we have previously reported, it is important for the Bureau to remain on schedule to keep downstream activities on track. As part of its 2020 Census schedule development, the Bureau divided the 14-year life cycle of the 2020 Census into five phases. The life cycle began in fiscal year 2009 with the Options Analysis phase. The second phase, Early Research and Testing, comprises work being done through the Bureau’s GSS-I program and the 2020 Research and Testing Program. This work is intended, in part, to explore how MAF/TIGER updates could be modified to control costs or improve quality. Figure 2 illustrates the sequencing of the five 2020 Census phases. The Bureau is taking a number of actions to help it develop a better understanding of the different sources available for updating address and mapping data and to better position it for cost reduction opportunities in data acquisition while increasing the quality of the MAF/TIGER database. According to Bureau officials, while more significant decisions on data sources remain, they have decided to initially use the following data sources to help improve address and mapping information in the 2020 Census MAF/TIGER database: sufficiently reliable address and geospatial data through GSS-I, provided by state, local, and tribal governments with active address and mapping efforts underway; address, aerial, and spatial data from other federal agencies; and imagery via a commercial source. GSS-I partnerships. As the Bureau continuously updates and maintains data in the MAF/TIGER database, Bureau officials have decided that state, local, and tribal governments that have data of sufficient quality— and that participate in GSS-I partnerships—will be the primary source of address and geospatial data in their geographic areas. For governments whose data passes a series of Bureau content and quality checks, the GSS-I partnership program data will be collected throughout the decade. According to current plans, state, local, and tribal governments that reliably maintain address lists (for purposes such as emergency response and property assessment) would be invited to share addresses with the Bureau throughout the decade, rather than only during the 2 years prior to the census, as was done for the 2010 Census. Federal agencies. Bureau officials have decided that some address, aerial, and spatial data will be collected from other federal agencies. Thus far, Bureau officials indicated that the federal agency data being used to update the MAF/TIGER address and spatial data for 2020 includes address data from the USPS Delivery Sequence File, and satellite imagery provided by the U.S. Department of Agriculture’s (USDA) National Agriculture Imagery Program and the National Geospatial- Intelligence Agency (NGA). These address, aerial, and spatial data are used to identify areas with growth or reduction in the number of housing units. Commercial sources. Bureau officials have decided to use a commercial imagery service, giving the Bureau the capacity to store and manage imagery it has already collected from other sources—such as local governments—and the ability to use imagery provided from the commercial vendor for areas where the Bureau lacks imagery data. The Bureau is exploring other options as well, including in-house use of imagery from other federal agencies or from additional commercial vendors. Additional data sources. In addition to these data source decisions, Bureau officials have been conducting ongoing research and outreach with a variety of entities to identify additional data source options the Bureau could use to meet its address and mapping needs. Table 1 describes data sources the Bureau has already identified that might possibly meet its address and mapping needs. As an example of work with entities outside the Bureau, during fiscal year 2011, the Bureau invited officials from USPS and the U.S. Geological Survey to participate in GSS-I research and development working groups to help identify sources for address and feature updates for the MAF/TIGER database. In September 2011, the Bureau hosted a meeting with state and local governments, nonprofit organizations, and various national associations to discuss techniques for address list development and maintenance, as well as potential pilot programs for data sharing among these groups. The Bureau has also taken steps to work with commercial vendors to review potential sources of commercial data that the Bureau could use to augment or verify data collected through GSS-I.