public high schools are graduating students within the expected period of 4 years.

Data presented in this report are drawn from the annual October Current Population Survey (CPS), the annual Common Core of Data (CCD) collections, and the annual General Education Development Testing Service (GEDTS) statistical reports. Data in the CPS files are collected through household interviews and are representative of the civilian, noninstitutionalized population in the United States, including students attending public and private schools. The CCD data are collected from state education agencies about all public schools and school systems in the United States, and contain aggregates of administrative record data kept by these agencies that are representative of all public school students in this country. The GEDTS data are also built from administrative record data keptfrom 2008) lack a high school credential (U.S. Department of Justice 2004, 2009). Although not strictly comparable because of different age ranges considered, estimates for those 25 and older in the general population during the same years indicate that about 15 percent were dropouts (U.S. Department of Commerce, Census Bureau 2004, 2007).

4 Levin and Belfield estimate costs at $209,000 as of 2004. The estimate here is adjusted for inflation between 2004 and 2008 using March 2004 and March 2008 consumer price indexes.

5 Trend analyses have shown a pattern of decline in event dropout rates prior to 1990, a brief upward trend from 1991 through 1995, and then another decline through 2008. As a result, in this report, overall trends from 1972 to 2008 are reported, as well as