For the latter two uses, however, both the timing of high school completion and the manner in which young people complete high school can be important. For instance, schools may be deemed successful at moving young people through to completion only if they obtain regular diplomas “on time,” typically within four years.

Given these differences in intended purpose, it becomes less puzzling to read in the Digest of Education Statistics that “73.4 percent of public high school students graduated on time,” despite the fact that only 9 percent of 16- to 24-year-olds were dropouts in 2006 (Snyder, Dillow, and Hoffman, 2009, p. 3 and Table 109). The former estimate is explicitly intended to describe the share of a cohort of students that has completed high school on time and by obtaining a diploma—essentially an attribute of schools. The latter estimate is clearly intended to describe the share of young people who are not gaining the human capital associated with high school completion. Presumably many of the 26.6 percent of ninth graders in fall 2002 who did not go on to graduate from high school with a diploma by spring 2006 were still enrolled or will compete high school later, via a GED or another alternative credential.1 Given the reported 9 percent dropout rate, one might presume that eventually about 91 percent of young people will eventually complete high school one way or another.2


Another source of differences in the rates is the data used in the calculations. A number of available data sources can be used for calculating the rates. These data were collected for different reasons using different types of designs—cross-sectional sample surveys, longitudinal sample surveys, cross-sectional administrative data, and longitudinal administrative data. The collection method and the reasons for collecting the data can affect the rates that are calculated. In this section, we describe the major data sources used in this country to compute high school dropout and completion rates and discuss their strengths and weaknesses in relation to the three purposes listed above.

Cross-Sectional Sample Surveys

The data most widely used for measuring high school dropout and completion come from the Current Population Survey (CPS),3 the U.S. decennial


100 percent – 73.4 percent = 26.6 percent.


100 percent – 9 percent = 91 percent.


Technically, CPS data are not cross-sectional, although they are often used as if they were. That is, if a subject is selected to respond to the CPS, the person is surveyed 8 times over 16 months, which makes the data longitudinal. Using the data longitudinally is technically very difficult, so they are rarely used in this way. We think this has contributed to the misconception that the data are cross-sectional rather than longitudinal.

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