Integrating and Distributing Administrative Data to Support Community Change

Need for Small-Area Data

Data about the well-being of demographic groups, families, institutions, the built environment, the natural environment, and businesses play an increasingly important role in a number of efforts to improve communities. Analysis at the individual person or property level is often impractical and perhaps unethical because of limited access owing to concerns about confidentiality and the amount of information contained in individual-level data sets. Data aggregated by small geographic areas, such as census tracts, neighborhoods, and service districts, avoid problems with confidentiality and allow for easier recognition of patterns across space and time. Access to small-area data can facilitate needs assessments, program planning, site selection, and resource allocation by public or private agencies. Small-area data can also support long-term community planning, serving as the basis for forecasts of demographic and housing changes as well as models of the desired impact that various programs might have. The increasing emphasis on measurable outcomes by funders, including private foundations and the federal government, has also increased the need for trend data to evaluate the impact of programs. The ability of communities to monitor the impact of government and private actions, including their ability to mount Community Reinvestment Act challenges, also depends on their access to appropriate small-area data.

The demand for small-area data has increased over the past century along with the number of small geographic units available to serve as units of analysis. In his classic small-area study of housing and economic conditions, The Philadelphia Negro, W. E. B. DuBois used the political ward as his focus (1899). Responding to the need for new geographic units that were not politically based and were less subject to boundary changes, the Census Bureau introduced census tracts (originally called districts) in 1910. Concerned that cities did not recognize the value of these new geographic tabulations, the American Statistical Association established a Committee on Census Enumeration Areas in 1931 to promote census tracts and identify uses for tract-level data (U.S. Department of Commerce, 1994). President Hoover's Committee on Social Trends relied on a combination of ward-, municipal-, and county-level data for Recent Social Trends, the comprehensive account of social conditions it published in 1933 (President's Research Committee on Social Trends, 1933). On the other hand, the Works Progress Administration Real Property Surveys, conducted later that decade, used census tracts and blocks to report extensive information about households and housing conditions. The U.S. Bureau of the Census first provided data at the block level in 1940, followed by the block group in 1970.

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