The enrollment figures are based on the National Center for Education Statistics Public Elementary/Secondary School Universe Survey files (NCES, 2008a). This is an annual census of the nation’s public schools conducted by the U.S. Department of Education in cooperation with the state education agencies. All public schools (regular, vocational, special education and others) are included in this analysis as long as they reported enrollments by race and ethnicity. In school year 1993-94, Idaho did not report public school enrollments by race/ethnicity. To conduct a pristine comparison of enrollments over time, schools in Idaho are omitted from the analysis. School year 1993-94 was utilized as the starting point for the analysis because prior to that even more states did not report enrollments by race/ethnicity.

A public school is classified as city/suburban/town-rural on the basis of the locale of its local education agency in 2006-07. All public schools are operated by a local education agency, and the National Center for Education Statistics (NCES) classifies local education agencies as serving city, suburban, town or rural locales (NCES, 2008b). The analysis uses the new locale codes in the 2006-07 Public Local Education Agency Survey file (the annual census of local education agencies also compiled by the NCES). NCES uses Census Bureau data on population density and proximity to urbanized areas to assign the locale of schools and local education agencies.

Public schools in 1993-94 were geographically classified by their 2006-07 local education agency locale. This is straightforward for most of the 83,000 public schools that were in operation in 1993-94. However, about 1,800 of those schools were run by local education agencies that ceased to exist by 2006-07. The 2006-07 locale of these schools and students could not be determined. These students were included in the 1993-94 counts, and they were allocated to the town/rural category. About 400,000 students (representing less than 1% of public school enrollment in 49 states and the District of Columbia) were in schools whose 2006-07 locale could not be determined.