Sections 1 through 4 of the report analyze county Hispanic and total population counts from the U.S. Census Bureau. The 2007 counts refer to July 1, 2007, and are from the bureau’s county population estimates program ( Population estimates are available for all 3,141 counties. The 1990 and 2000 county population counts derive from the decennial Census and refer to April 1 of the Census year. These are published in the decennial Census SF1 files and are obtained from the responses to the Census short form questionnaire. The short form responses are solicited from 100% of the resident population and not a sample of the population. For 2000 we used the April 1, 2000, counts in the base of the county population estimates program. These include small post-enumeration corrections from the SF1 figures.

Section 5 examines characteristics of the Hispanic and non-Hispanic population. The bureau’s county population estimates program cannot serve as the source for this analysis because it does not possess detailed population characteristics (only population aggregates). Detailed population characteristics at the county level can be obtained from the public use micro samples of the Decennial Census and the American Community Survey (ACS). The ACS is a sample of the resident population. Hispanic population information is not available for all 3,141 counties in the ACS.

Unfortunately, counties are not identified in the Census public use micro samples. The smallest level of geographic detail is the public use microdata area. PUMAs can be aggregated to form single counties or county groups. A further complication is that the PUMA definitions for the 1990 Census do not match the PUMA codes for the 2000 Census and 2007 ACS. See for further details. Using a PUMA-to-county crosswalk developed by Pew Hispanic Center senior demographer Jeffrey S. Passel, we are able to identify 608 county/county groups on a consistent basis in the 1990 5% IPUMS, 2000 5% IPUMS and the 2007 ACS Integrated Public Use Micro Sample.

The 608 county/county groups cover the entire United States. For the 585 county/county groups that have at least 1,000 Hispanics in 2007, the distribution of Hispanic growth in the new century mirrors the distribution of growth for the 1,362 counties using the Census Bureau population estimates. Again using the distinction between county/county groups in which the Hispanic population grew faster than the median county, we identify county/county groups as either fast-growing or slow-growing Hispanic county/county groups. The aggregate Hispanic population in the fast-growing and slow-growing county/county groups is nearly identical to the analysis using the 1,362 county population estimates.