at the end of the second case study, in the interest of answering the question of whether local administrative data on voters can be used instead of or in addition to the ACS data in Voting Rights Act analyses. Returning the focus to Monterey County, California—a jurisdiction for which she has done a lot of redistricting work—Gobalet said that she has had the opportunity to do detailed geocoding and surname analysis of the voter rolls. She emphasized that surname analysis might be feasible for Spanish-origin names but is not believed to be reliable for identifying blocs of other minority groups; African American surnames are not distinctive enough to be singled out, and she said that the methodology has been found to have limited utility for identifying Asian American voters. But—if workable to identify Hispanic voters—the surname-based voter roll data has the attractive feature of being linked to precise addresses (and thus exact geographic locations) that can be linked to arbitrarily small geographic areas.

Gobalet said that her work with the Monterey County registered voter data has suggested fairly strong concordance between the 2006–2010 ACS CVAP tabulation and the surname-based Hispanic voter shares, with the latter computed separately from registered voter rolls as of November 2008 and the rolls as of November 2010. Monterey County is subject to U.S. Justice Department pre-clearance of districting plans under the Voting Rights Act, so she conducted this work in the context of evaluating two alternative districting plans partitioning the county into five districts—one developed by county authorities (and ultimately adopted) and a last-minute alternative proposal backed by the county’s largest city, Salinas. Across both proposals and both vintages of the surname-based Hispanic shares, the Hispanic CVAP percentage and Spanish-surnamed registered voter share differed by no more than 5 percent for any district. She concluded that it is reassuring that both data sources seem to be measuring the same basic thing so, in some cases, it may not be necessary to rely solely on the Hispanic CVAP data from the ACS. That said, she reiterated that the CVAP data have more utility for examining concentration of minority groups other than Hispanics.

She closed by repeating her bottom-line conclusion from all three case studies—that the ACS-based CVAP special tabulation has become essential to ensure compliance with the letter and intent of the Voting Rights Act. Absent the ACS, things would necessarily return to the days of basing important determinations on guesswork and hunches.


Andrew Beveridge (Queens College and Graduate Center, City University of New York, and Social Explorer, Inc.) began his remarks by describing himself as “sort of an accidental demographer; I stumbled into this field without knowing too much about it, after graduate school.” Getting involved in civil

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