Part II
Issues of Census Design



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Reengineering the 2010 Census: Risks and Challenges Part II Issues of Census Design

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Reengineering the 2010 Census: Risks and Challenges CHAPTER 3 Modernizing Geographic Resources A DECENNIAL CENSUS IS FUNDAMENTALLY an exercise in geography. The root constitutional mandate of the census explicitly links it to the nation’s electoral geography, as the census serves as the basis for shifting states’ representation in the U.S. House of Representatives every 10 years to match population shifts over the decade. Each new decennial census also offers new perspectives on the nation’s civic geography, providing rich information on how and where the American public lives and how the characteristics of small geographic areas and population groups have changed with time. In order to produce this information, the Census Bureau requires a great deal of accurate, raw geographic data—a full and complete address list and a mechanism by which those addresses can be associated with specific locations. Without this raw information, it would be impossible for the census to achieve its goal of counting each resident once and only once and within a precise geographic boundary. As the panel stated in its first interim report, “the address list may be the most important factor in determining the overall accuracy of a decennial census” (National Research Council, 2000a:35).

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Reengineering the 2010 Census: Risks and Challenges The “three-legged stool” strategy outlined by the Census Bureau for the 2010 census calls for modernization of the Bureau’s primary geographic resources: the Master Address File (MAF), the source of addresses not only for the decennial census but also for the Census Bureau’s numerous survey programs; and the Topologically Integrated Geographic Encoding and Referencing System (TIGER), a database describing the myriad geographic boundaries that partition the United States. The specific set of activities that the Census Bureau has described to achieve this modernization is known as the MAF/TIGER Enhancements Program (MTEP), an “8-year, roughly $500 million undertaking” (U.S. Department of Commerce, Office of Inspector General, 2003). Given its nominal goal, the MTEP may be of paramount importance in terms of its potential impact on the quality of the 2010 census. However, the critical word in that statement is “nominal” since the term “MAF/TIGER Enhancements Program” suggests significant enhancements to both the MAF and TIGER. We do not argue that TIGER is unimportant; it is a critical geographic resource for census needs and it is in dire need of modernization. However, the MAF/TIGER Enhancements Program is oriented overwhelmingly toward TIGER and does little to enhance—to improve—the MAF. The Census Bureau’s strategy for dealing with the MAF is, to an unfortunate degree, little more than routine maintenance—seemingly deferring active attention to the MAF until a complete block canvass very late in the census cycle (thus repeating a costly operation from 2000 that had been implemented as an eleventh-hour fix). The panel’s unease regarding the Bureau’s prospects for making material progress in improving its geographic resources for 2010 is further heightened by the apparent lack of comprehensive and realistic plans and schedules for the TIGER modernization effort. In this chapter, we briefly review the development of both the MAF and TIGER (Section 3-A) before discussing the details of the MAF/TIGER Enhancements Program (3–B). Our general assessment of the program follows (3–C), with our particular

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Reengineering the 2010 Census: Risks and Challenges call for attention to MAF improvement discussed separately in Section 3-D. Our recommendations—including designation of a MAF coordinator, strengthened geographic partnerships, and empirical justification of potential address sources—are detailed in Section 3-E. 3–A DEVELOPMENT AND CURRENT STATE OF THE MAF AND TIGER Before we discuss the specific enhancements program that has been initiated by the Census Bureau, it is useful to first briefly review the nature and status of the two geographic systems addressed by the package. 3–A.1 The Master Address File Purpose and Scope The Master Address File (MAF) is the Census Bureau’s complete inventory of known living quarters and business addresses in the United States and its island areas. The MAF contains a mailing address for each of those living quarters, if one exists. For housing units or living quarters without mail addresses, descriptive addresses (e.g., “2-story colonial with dormer windows”) may be coded. The MAF also includes an intricate set of flags and indicators that denote the operations that added or edited each address. It does not, however, record the date or time when an address was entered in the file or when it was modified. In principle, the MAF is a constantly evolving and continually updated resource; the “snapshot” of the MAF that is extracted and used to conduct the census is called the Decennial Master Address File, or DMAF. Construction of the 2000 Census Master Address File The concept of a continuously maintained MAF is a relatively new one; in the 1990 and earlier censuses, address lists were compiled from multiple sources prior to the census (e.g., lists were purchased from commercial vendors) and were not retained after the census was complete. The practice of maintain-

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Reengineering the 2010 Census: Risks and Challenges ing the address list—to support not only the decennial census but also the Census Bureau’s other survey programs—was initiated after the 1990 census. In part, writes Nash (2000:1), “a major impetus for this change was the undercounts experienced in the 1990 and earlier decennial censuses, nearly a third of which was attributed to entirely missing housing units.” An initial MAF was constructed using the city-style addresses1 on the Address Control File (ACF) developed for the 1990 census (Hirschfeld, 2000). To populate the MAF, the Census Bureau “devised a strategy of redundancy using a variety of sources for addresses,” thus “[assuming] responsibility for developing a comprehensive, unduplicated file of addresses” (Nash, 2000:1). Most prominent of the update sources were two that were endorsed by one of our predecessor Committee on National Statistics (CNSTAT) panels on the decennial census (National Research Council, 1995:5), which recommended that the Census Bureau “develop cooperative arrangements with states and local governments to develop an improved master address file” and that the U.S. Postal Service be given “an expanded role” in census address list operations. Both these recommendations were significant in that they required legislative authority in order to operate within the prohibition on release of confidential data codified in U.S. Code Title 13, the legal authority for census operations.2 Congress granted this authority in the Census Address List Improvement Act of 1994 (Public Law 103-430). The Delivery Sequence File One provision of the Census Address List Improvement Act authorized the Census Bureau to enter into a data-sharing arrangement with the U.S. Postal Service, 1   A city-style address is one that can be specified by a numeric identifier (e.g., 305) in combination with a street name (e.g., Park Avenue), possibly with a specific subunit or apartment identifier. By comparison, non-city-style addresses are those that cannot be mapped to particular streets in this fashion, such as “Rural Route, Box 7” or a post office box. 2   In Baldrige v. Shapiro, 455 U.S. 345 (1982), the U.S. Supreme Court ruled that the Census Bureau’s “address list … is part of the raw census data intended by Congress to be protected” under the confidentiality provisions of Title 13. Accordingly, the Court concluded that the Bureau’s address list is not subject to disclosure under the Freedom of Information Act or under the discovery process in civil court proceedings.

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Reengineering the 2010 Census: Risks and Challenges under which the Postal Service would regularly share its Delivery Sequence File (DSF) with the Census Bureau.3 The DSF is the Postal Service’s master list of all delivery addresses served by postal carriers.4 The name of the file derives from the Postal Service-specific data coded for each record along with a standardized address and ZIP code: namely, codes that indicate how the address is served by mail delivery (e.g., carrier route and the sequential order in which the address is serviced on that route). The DSF record for a particular address also includes a code for delivery type that is meant to indicate whether the address is business or residential. Because the census is conducted largely through mailed questionnaires—most of which are subsequently mailed back—the U.S. Postal Service is a crucially important conduit in the census process. Moreover, the Postal Service is a constant presence in the field, servicing existing and emerging routes on a daily basis. For these reasons, securing access to the DSF was a major accomplishment. But while the DSF is an undoubtedly vital source of address information, it is incomplete for census purposes both because the list of mail delivery addresses is only a subset of the complete list of housing units in the United States and because it does not always properly distinguish multiple housing units within the same structure. The Postal Service began sharing the DSF with the Census Bureau in the mid-1990s. Currently, as part of the Bureau’s ongoing Geographic Base Support Program, new versions of the 3   Specifically, the legislation text indicates that “the Postal Service shall provide to the Secretary of Commerce for use by the Bureau of the Census such address information, address-related information, and point of postal delivery information, including postal delivery codes, as may be determined by the Secretary to be appropriate for any census or survey being conducted by the Bureau of the Census. The provision of such information under this subsection shall be in accordance with such mutually agreeable terms and conditions, including reimbursability, as the Postal Service and the Secretary of Commerce shall deem appropriate.” 4   The list does not include general delivery addresses. Additional information on the DSF and commercial programs under which private companies are able to match their own address lists against the DSF can be found on the U.S. Postal Service Web site at http://www.usps.com/ncsc/addressservices/addressqualityservices/deliverysequence.htm [3/1/04].

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Reengineering the 2010 Census: Risks and Challenges DSF are shared with the Bureau twice per year and updates or “refreshes” to the MAF are made at those times. Local Update of Census Addresses The Census Address List Improvement Act of 1994 also authorized the secretary of commerce and the Census Bureau to “provide officials who are designated as census liaisons by a local unit of general purpose government with access to census address information for the purpose of verifying the accuracy of the address information of the bureau for census and survey purposes.” The act obligated the Census Bureau to “respond to each recommendation made by a census liaison concerning the accuracy of address information, including the determination (and reasons therefor) of the bureau regarding each such recommendation.” The act thus permitted the Census Bureau to share with a local or tribal government for review and update the address data it had on file for that locality. To preserve Title 13 confidentiality, the information to be disclosed to any particular locality was limited to address information and to the set of addresses for that area. Ultimately, the address information would be shared with local or tribal governments only if they signed an agreement to keep it confidential and to dispose of it when finished with review. In August 1996, the Census Bureau initiated a program to acquire address list information from local governments. The Program for Address List Supplementation (PALS) contacted local and tribal governments (along with regional planning agencies) and solicited whatever lists of city-style addresses they maintained for their jurisdictions. However, the Bureau quickly concluded that the program was troubled: local address lists were not necessarily in computer-readable format, or were not formatted in such a way (including apartment and unit designators) as to match with the emerging coding system for the MAF. More significantly, response by local governments to an open-ended query for local address lists—ideally coded to the appropriate census block—was low. The program was officially terminated in September 1997 (U.S. Census Bureau, Geography Division, 1999). The Census Bureau’s next attempt at local geographic part-

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Reengineering the 2010 Census: Risks and Challenges nerships followed more closely the Address List Improvement Act by releasing parts of the Census Bureau’s MAF for review rather than requesting entire address lists. The resulting program became known as the Local Update of Census Addresses (LUCA), though it is also occasionally referred to as the Address List Review Program. LUCA was conducted in two waves: LUCA 98. In 1998, local and tribal governments in areas with predominantly city-style addresses were given the opportunity to review the Census Bureau’s address list. Bureau cartographers used blue lines to distinguish city-style from non-city-style address areas on the maps that defined eligibility for LUCA. As a result, LUCA 98 was said to target localities lying “inside the blue line.” LUCA 99. In 1999, attention turned to areas outside the “blue line,” those with non-city-style addresses.5 Local and tribal governments were again invited to review Census Bureau materials, but this time the offer was to review block-level counts of housing units rather than actual addresses. To participate in LUCA, local and tribal governments were required to identify liaisons who would handle the address list materials and take an oath of confidentiality. Materials were then sent to the governments, which had a specified time period to review them and submit any proposed changes. These changes were then reviewed by the Census Bureau, which often opted to reject part or all of the localities’ suggested additions or deletions to the address list. An appeals process was set up under the auspices of the Office of Management and Budget (OMB), giving local and tribal governments a final opportunity if they found grounds to quarrel with the Census Bureau’s judgments. The Working Group on LUCA commissioned jointly by this panel and the Panel to Review the 2000 Census conducted an ex- 5   The “blue line” designating LUCA 98 and 99 areas was not constrained to follow borders of whole geographic locations, so many places and counties were eligible to participate in both waves of LUCA. In some localities, the blue line did not cleanly distinguish between city-style and non-city-style areas, causing frustration for some LUCA participants (Working Group on LUCA, 2001). The process for delineating city-style-address areas should be refined for future LUCA-type programs.

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Reengineering the 2010 Census: Risks and Challenges Box 3.1 Results of LUCA Working Group Study The Working Group on LUCA commissioned jointly by this panel and the Panel to Review the 2000 Census was composed of state and local government personnel who had been involved in their area’s participation in the Local Update of Census Addresses (LUCA) program. The working group conducted a sample survey of LUCA-participant governments, inquiring about the techniques and resources they employed in order to complete a review of their local MAF segment. The working group report also provides detailed case study reports of LUCA participation, ranging in scope from rural communties to efforts at the state level to coordinate localities’ participation in LUCA. The working group also analyzed available data on local and tribal government participation, including the numbers of addresses submitted by governments and accepted or rejected by the Bureau. However, available data did not allow for assessment of the number of completed census enumerations obtained using addresses added uniquely or in part by LUCA. The working group issued its final report in 2001. The working group’s analysis (Working Group on LUCA, 2001) led it to identify three principal barriers to effective local government particpation in LUCA: Inaccurate designation of the “blue line” separating city-style and non-city-style address areas: Localities expressed frustration at inaccuracies in drawing the boundaries used to distinguish the LUCA 98 program (reviewing specific addresses for city-style addresses) and the LUCA 99 program (reviewing block-level counts of housing units for non-city-style address areas). In some cases, the distinguishing “blue line” put portions of cities with seemingly valid city-style addresses into LUCA 99 territory, thus hampering localities’ opportunity to offer specific address corrections. Inconsistent designation of subunit identifiers: Differences in reporting identifiers such as apartment or unit number made it difficult to match MAF extracts to local records. Addresses rejected due to inaccuracies in TIGER: As a consequence of out-of-date line features in the TIGER geographic databases, local address submissions were sometimes rejected because the addresses could not be geocoded based on current TIGER files. That is, seemingly accurate addresses were rejected because TIGER did not contain a new road or because the road’s name or designation had changed. The timing of the LUCA program leading to the 2000 census was also a concern to participants. Even large local governments with complete local geographic information files found it difficult to meet the turnaround time required for submission of addresses to the Census Bureau. The problem may have been compounded for local governments with less-developed geographic resources and in cases where manual review of address lists was the best or only available option; indeed, tight timelines combined with the requisite investment of resources may have dissuaded some governments from participation.

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Reengineering the 2010 Census: Risks and Challenges The working group found some evidence of increased participation and local cooperation in cases where state, regional, or county organizations worked to coordinate responses by multiple governments, sometimes providing a valuable “LUCA education” function. Improved training and guidance on the expectations of the program were identified as possible factors for increasing partipation in a LUCA-style program for the 2010 census. tensive review of the LUCA process from the participants’ (local government) perspective (Working Group on LUCA, 2001). The working group’s principal findings are summarized in Box 3.1. Block Canvass In the 1990 and earlier censuses, when address lists were not maintained from census to census but rather assembled before the decennial enumeration, a complete field canvass of the city-style addresses in designated mailout/mailback areas was a standard—but costly—operation. The Census Bureau had hoped to avoid a complete block canvass before the 2000 census; in introducing the Address List Improvement Act of 1994, U.S. Representative Thomas Sawyer expressed hope that “collection and verification of address information in primarily electronic format” from the Postal Service and local governments “will greatly reduce the amount of precensus field canvassing,” an activity that he indicated had proven “expensive and often inaccurate.”6 Rather than a complete block canvass, the Census Bureau planned to target specific areas with coverage gaps and focus field canvass activities on those areas. In spring and summer 1997, as a continuous MAF began to take shape, optimism about the completeness of DSF updates gave way to doubts when it also became clear that PALS was not proving an effective means to obtain address information from local and tribal governments. Internal evaluations convinced the Bureau that relying on DSF and LUCA alone could leave gaps in MAF coverage; in particular, the Bureau was concerned that “the DSF file missed too many addresses for new construction and 6   Representative Sawyer’s remarks can be found in the Congressional Record for the 103rd Congress, page H10618 (October 3, 1994).

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Reengineering the 2010 Census: Risks and Challenges 3–E.2 Coordinate Responsibility for the MAF In Chapter 6, we advocate the creation of a new position within the Census Bureau—a system architect for the decennial census—with the primary goal of integrating and coordinating work on architecture remodeling. We believe that improving the MAF is likewise an area that would benefit greatly from focused staff effort. At least three major divisions within the Bureau (Geography, Field, and Decennial Management; see Box 2.2) have a strong stake in the maintenance and use of the MAF as it pertains to the decennial census, and the Demographic Surveys division also has a stake given MAF use in conducting the Bureau’s household surveys. Given the legitimate (but sometimes competing) interests of the various divisions, it would be useful to vest responsibility for coordinating MAF improvement and research in one office with both the connections and the ability to work with all relevant divisions. We reiterate a recommendation from our second interim report (National Research Council, 2003a:Rec. MAF–2): Recommendation 3.2: The Census Bureau should create and staff a position to oversee the development and maintenance of the MAF as a housing unit inventory, with a focus on improving methods to designate, list, and update units. This position should be responsible for development and implementation of plans drawn up consistent with Recommendation 3.1. Census Bureau staff expressed skepticism about this recommendation in their reaction to the second interim report at the panel’s final public meeting in September 2003, arguing that the Bureau’s organization is not given to the creation of centralized “czar” positions. That argument, however, underscores the point of this and several other recommendations in this report: real integration in achieving census objectives will require some thinking outside the lines of existing organizational trees. In our assessment, the Census Bureau’s approach of handling MAF issues by committee is ineffective and leads to serious underutilization of the Bureau’s existing staff and resources; MAF development should be supported with a clear structure of orga-

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Reengineering the 2010 Census: Risks and Challenges nization and accountability, as the Enhancements Program has done for TIGER. 3–E.3 Improve Research on the Delivery Sequence File Our next four recommendations call for the development of an empirical, research-based approach to MAF updating efforts throughout the decade. Each prospective address input source should be carefully examined, weighing strengths, weaknesses, and costs, and reasonable estimates of the source’s potential contribution to the 2010 MAF should be produced. The U.S. Postal Service’s Delivery Sequence File provides twice-yearly “refreshes” to the MAF under the Census Bureau’s current geographic support system. The efficacy of these updates—in general, and differentially by geography and urban/rural status—has not yet been fully demonstrated. Recommendation 3.3: The Census Bureau should pursue more effective partnership and research collaboration with the U.S. Postal Service, including but not limited to further work on “undeliverable as addressed” items from the 2000 census, assessment of the address coverage quality of the Delivery Sequence File (DSF), and possibilities for more accurate translation of post office box listings and other DSF entries to street addresses and geographic coordinates. 3–E.4 Define the Role of the Community Address Updating System Objective Four of the MAF/TIGER Enhancements Program—CAUS—has been delayed in implementation due to the lack of initial funding for the ACS. The expectations for CAUS have never been entirely clear. As we noted in Section 3-D.1, the system has been described as vital to securing address updates “in rural areas with non-city-style addresses,” which represent approximately 15 percent of the population (U.S. Census Bureau, 2003c:9). However, at the panel’s last public meeting in September 2003, senior Census Bureau staff commented that not much

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Reengineering the 2010 Census: Risks and Challenges would be lost if CAUS were not fully implemented, contingent as it is on funding of the ACS. However, the Census Bureau has indicated that it trained 400 field representatives on CAUS methodology in August 2003, began listing operations in October 2003, and has continued to refine the ALMI GPS-equipped laptop computer used to collect CAUS data (U.S. Census Bureau, 2003e:4). In light of these investments, as 2010 planning proceeds, the Bureau needs to make clear the expectations for CAUS, including assessment of the long-term feasibility of the activity and of its potential contribution to the 2010 MAF. If CAUS is indeed crucial to securing updates from rural areas, given the uncertainty about the program’s implementation, consideration needs to be made as to whether alternate sources could provide the information. Recommendation 3.4: The Census Bureau should assess how critical the Community Address Updating System (CAUS) is to providing address updates in rural, non-city-style address areas. Such an assessment should include not only estimates of the number of addresses that could be provided and the workload that could be handled by CAUS/American Community Survey staff, but also empirical evidence on coverage gaps in the U.S. Postal Service’s Delivery Sequence File by geographic area or type. 3–E.5 Plan Local Geographic Partnerships and Implement Early To its credit, the Census Bureau has recognized the importance of partnerships with local and tribal governments by designating their creation and maintenance as Objective Three of the Enhancements Program. The Bureau’s RFP for the TIGER realignment of Objective One makes this clear, noting that “the success of [Objective One], and the continuous update of the information in MAF/TIGER, requires ongoing interaction between the Census Bureau and its federal, state, local, and tribal government geographic partners.” However, the Bureau has not provided a clear indication of how such partnerships would work.

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Reengineering the 2010 Census: Risks and Challenges While the panel acknowledges that the funds available for expanding and encouraging geographic partnership options have been limited, the cryptic descriptions of Objective Three that we have received do not make clear how and when the Bureau intends to involve local and tribal partners in these programs. A major stated role for local and tribal geographic partners is to contribute to Objective One by sharing their current GIS files with the Census Bureau to support TIGER realignment. But in this matter, and in past geographic interactions such as LUCA, the Census Bureau has often approached “partnership” as a one-sided exchange: “partners” expend resources and turn information over to the Bureau. The principal reward to a local or tribal government for entering into such a partnership is definitely not trivial: the prospect of a more accurate census count. The panel recognizes that the Census Bureau is not a fund-granting organization and hence cannot directly subsidize local or tribal governments to improve and submit their geographical resources. That said, the Bureau should aim for partnerships that are true exchanges of information: for instance, by giving census field and regional staff an increased role in interacting with local and tribal authorities and collecting information updates. At the very least, steps should be taken to lessen the burden of partnership on the local and tribal governments—for example, by conducting LUCA-like address list reviews electronically with submissions via the Internet, and coordinating the various geographic data collection programs so that localities are not asked for similar information in different formats by different divisions of the Census Bureau. The Census Bureau needs to articulate a plan for communication with localities that takes advantage of existing structures, including the State Data Center Network, the Federal-State Co-operative Program for Population Estimates, state and regional councils of governments, and other local governmental entities. The role of the Census Regional Office Geographic Coordinators relative to these entities and to Census Bureau headquarters needs to be spelled out. The ability and willingness of different governments to join forces with the Census Bureau vary widely. It is inevitable that local efforts will be differentially expressed in different areas of

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Reengineering the 2010 Census: Risks and Challenges the country, whether such efforts involve mapping, address listing, or the nurturing of partnerships. While all areas should receive equal treatment in the spirit of fairness, local interest, feasibility, and cost-effectiveness might well dictate otherwise. Moreover, although geographic partnerships with local and tribal governments can be useful to tap the knowledge and expertise of those closest to the field, variations in GIS usage may affect the accuracy of local and tribal government geographic resources and may introduce errors when combined with census resources. In the interest of effectiveness, we recommend careful analysis of the successes and failures of prior LUCA programs in order to properly conduct future community participation programs. Close evaluation of the 2000 address file by type of enumeration area, by dwelling type, by the contribution of geographic update programs like LUCA, and by region of the country—highlighting areas where elicitation of local and tribal information may be most beneficial—is surely required if the Census Bureau is going to maintain the MAF in a cost-effective manner in the years leading to the 2010 census. The Bureau’s future plans for LUCA and other partnership programs should also provide for evaluation of those partnerships, not only to inform the effectiveness of local contributions from the census perspective but also to give feedback to participating local and tribal governments. We reiterate a recommendation from our second interim report (National Research Council, 2003a:Rec. MAF–3) and add two other points on the nature of partnerships: Recommendation 3.5: The Census Bureau should immediately develop and describe plans for partnerships with state, local, and tribal governments in collecting address list and geographic information. Such plans should include a focus on adding incentives for localities to contribute data to the census effort, making it easier for localities and the Bureau to exchange geographic information. Accordingly, plans for partnerships should include: clear articulation of realistic schedules for local input and review;

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Reengineering the 2010 Census: Risks and Challenges definition and clear presentation of benchmark standards for local data to be submitted to the Bureau; mechanisms for providing effective feedback to local and tribal governments, detailing and justifying the Bureau’s decisions to use or not use the information provided; and coordination of efforts across the Bureau so that calls for local and tribal entities to supply input to the Master Address File, TIGER, the Boundary and Annexation Survey, and other Bureau programs are not unduly redundant and burdensome. 3–E.6 Justify the Complete Block Canvass In Section 3-D.2, we commented on Census Bureau reaction to the assumption, stated in our second interim report, that the Bureau hoped to forestall a complete block canvass in the 2010 census. Our commentary in the interim report continued (National Research Council, 2003a:66): In the absence of evidence that the combination of DSF and LUCA leading up to 2010 can overcome the last-minute doubts that arose in the late 1990s and without a clearer plan for CAUS—it is difficult to see how a full block canvass can be averted. We continue to stand by this assertion, and have called for development of empirical evidence on possible DSF, CAUS, and LUCA contributions to the 2010 MAF. Likewise, we believe that the Census Bureau’s decision to proceed with a full block canvass should also be justified with empirical evidence. We do not suggest that block canvassing is an idea that lacks merit. The evaluations of the 2000 census suggest that the effort contributed many addresses to the MAF (Burcham, 2002; Vitrano et al., 2003) and was generally very good at verifying existing units. However, evidence also suggested relatively high rates of inconsistency (22–24 percent) between addresses added or deleted by the block canvassing operation and results in the

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Reengineering the 2010 Census: Risks and Challenges census; an example of an inconsistency is a housing unit added by block canvassing but then found during the census operations to be an invalid housing unit (Burcham, 2002:38–39). We believe it rash to commit to such an expensive operation as full block canvassing absent both a compelling base in empirical evidence and a determination that targeted canvasses in specific (e.g., fast-growth suburban) areas are infeasible. It is decidedly a mistake to consider a full block canvass without early attention to effective canvass techniques for all types of housing stock, particularly small multiunit structures (see Section 5-C.1). The panel is also concerned that reliance on a block canvass may send unfortunate mixed messages about the relative quality of the address list needed for different purposes—that special operations are needed to derive an address list of presumably higher quality than that needed for the Census Bureau’s other surveys and, particularly, the ACS. We therefore recommend: Recommendation 3.6: The Census Bureau should evaluate the necessity of its plans to conduct a complete block canvass shortly before the 2010 census. Such justification must include analysis of extant census operational data and should include, but not be limited to, the following: arguments as to why selective targeting of areas for block canvass is either infeasible or inadequate, and as to how the costs of the complete block canvass square with the benefits; and analysis of how a full block canvass fits into the Census Bureau’s cost assumptions for the 2010 census. If plans proceed for a complete canvass, the Bureau should also consider how such a mass field deployment prior to 2010 could be used to achieve other improvements or efficiencies, such as the collection of GPS trace data as supplement to or as quality control for the TIGER realignment.

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Reengineering the 2010 Census: Risks and Challenges 3–E.7 Exploit 2000 MAF Data, and Redesign MAF for Evaluation in 2010 A recurrent theme in our preceding remarks is that there is a strong need for empirical assessment of the quality of potential address sources for the 2010 MAF. The natural starting place for such an evaluation would be the Census Bureau’s MAF Extract. Based on the 2000 census Decennial Master Address File—the “snapshot” of the MAF used to generate census mailing labels and to monitor mail response—the MAF Extract includes “flags” that indicate which of several sources contributed the address to the MAF. The MAF Extract also contains selected outcome measures, such as whether the address record was actually used in the 2000 census and whether it was tagged as a potential duplicate during the ad hoc duplicate screening program of early to mid-2000 (Nash, 2000). The MAF Extract has certain liabilities, chief among them that the system of flags used to indicate the source of an address does not show the complete history of an address in the MAF. Other than a rough temporal ordering of the input sources themselves, it is usually impossible to determine which source first contributed the address. Nonetheless, the extract is critical to answering key questions about the MAF-building process, and the panel continues to urge that the data resource be tapped for as much information as possible. Analyses of the MAF Extract should consider the type of enumeration area for each address in the 2000 census (e.g., mailout/mailback or update/leave) as well as geographic region. The main objective of the analysis is not to highlight how different areas of the country may have fared under various programs, but rather to obtain knowledge of how people in those areas respond and interact with census activities in order to improve planning for future census programs. Some key questions to address through Census 2000 evaluations are the following: Why were addresses included in the MAF but not in the 2000 census? This question provides perspective for the others on this list and is a good starting place.

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Reengineering the 2010 Census: Risks and Challenges How useful were the DSF updates in the identification of new units, especially in high-growth areas of the nation? The goal is to examine how much of the newest housing was picked up in a timely fashion by the U.S. Postal Service. The answers can provide valuable clues about the effort the Census Bureau should put into other avenues (e.g., new construction programs) as sources of information on new housing. How effective were LUCA inputs relative to what was already known (or was promptly seen) in a DSF update? Of those contributions that can be determined as “unique,” how many governments were represented and what kind of housing do these addresses represent? While LUCA must be conducted as part of the preparation for the 2010 census, the resources the Census Bureau chooses to expend on it can vary dramatically. The answer to this question can also inform strategies for the LUCA program for 2010. What were the original sources of address records that were deleted in the ad hoc duplicate identification and removal process conducted in 2000? Duplication related to address listing anomalies can be rectified once the specific problems with the duplicate addresses have been identified. Identifying the original source of the affected addresses is a prime means for doing that. What were the original sources of addresses that were flagged as potential duplicates but later reinstated? This question addresses the hypothesis that some addresses, originally considered as potential duplicates, were put back into the census in error. The Census Bureau already has an estimate of this number. By identifying the original sources of these addresses, the Bureau will have valuable clues about what produced this problem and how to avoid it in the future. What were the original sources of addresses for housing units where an interview was not obtained in nonresponse follow-up (NRFU)?

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Reengineering the 2010 Census: Risks and Challenges One hypothesis about the shortfall of long-form data in the 2000 census posits that NRFU enumerators encountered high levels of resistance from respondents who were being enumerated for the first time (some of whom escaped detection in 1990). Where did the addresses of these tough-to-enumerate units fall? (Of course, this is not the only or most likely hypothesis to explain problematic long-form data, but the question warrants attention and the Census Bureau’s MAF Extract data may be able to provide useful information.) What were the original sources of addresses for housing units that were subsequently declared nonexistent or were not found in NRFU? NRFU enumerators had the option of entering codes for “cannot locate,” “duplicate,” and “nonresidential,” among others, as reasons for listing a unit as “nonexistent.” Were these potential duplicates added back in, were erroneous addresses brought in from LUCA that were not detected by the Census Bureau, or were these problem addresses disproportionately from some other original source? For cases where a unit was determined not to exist in coverage improvement follow-up (CIFU; the final follow-up stage during the actual fielding of the census), what was the original source of the address? How many addresses were erroneously kept in the census and then deleted when the Bureau went out to check in CIFU? The Census Bureau’s topic report on address list development (Vitrano et al., 2003) is a step toward answering these questions. In particular, it makes strides toward managing the poor and confusing MAF codes indicating operations that added or edited the address in order to ascertain the original source of each address record. But it is only a step. Accordingly, we recommend: Recommendation 3.7: The Census Bureau must: fully exploit the address source information in the MAF Extract in order to complete 2000 cen-

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Reengineering the 2010 Census: Risks and Challenges sus evaluations, fill gaps in knowledge remaining from the 2000 census evaluations, and assess causes of duplicate and omitted housing units; and build the capability for timely and accurate address evaluation into the revised MAF/TIGER data architecture, including better ways to code address source histories and to format data sets for independent evaluation.