At the outset, we clarify what this paper does and does not do. We estimate high school graduation rates. We are not estimating the stock of skilled labor by educational category, although that would be a useful task.6 We are also not presenting a quality-adjusted high school graduation rate. Such a rate would adjust graduates, dropouts and GEDs by a scale reflecting the value of the stated education level in production.7 We also do not estimate the option value conferred by the degree.8 Like Mishel and Roy (2006), we are interested in estimating the high school graduation rate – the rate at which individuals in cohorts graduate high school through a normal process of matriculation, seat time and formal graduation.
In what follows, it is important to distinguish between a “completer” and a “graduate”. Following the NCES convention, we use the term “high school completer” to indicate a person who either graduated high school or obtained an alternative credential (e.g., GED). High school graduates are those who receive a traditional high school diploma from an accredited high school program.
Using household surveys, school administrative data and longitudinal surveys, we recalculate national high school graduation rates by race and gender. We discuss the problems and limitations of each data source in detail and show that, after adjusting for a variety of sources of discrepancy among alternative measures, all of these data sources give a consistent picture of U.S. graduation rates.
A. Census and CPS-Based Estimates
The Current Population Survey (CPS) is a monthly survey of approximately 50,000 U.S. households administered by the Bureau of Labor Statistics. It is primarily designed to track employment and earnings trends in the civilian non-institutional population.9 The CPS also collects the educational status of each household member.
Every October, the CPS administers an educational supplement that asks detailed questions concerning the educational history and attainment level of each household member. The NCES uses this data to calculate the 18- to 24-year-old status completion rate depicted in Figure I. Several recent papers have discussed the problems that arise from using the status completion rate as a measure of secondary school performance (see, e.g., Chaplin , Greene , Mishel and Roy , Sum et al. , and Swanson and Chaplin ). These studies claim that the status completion rate is a poor measure of the high school graduation rate because: (1) GED recipients are counted as high school graduates; (2) institutional and military populations are excluded from the CPS; (3) one household member responds for the entire household roster (proxy response bias); (4) the CPS is not able to locate all persons eligible for the survey (low sample coverage); and (5) recent immigrants, who were never enrolled in U.S. secondary schools, are included in the estimates.
Using decennial Census data, we assess the importance of each of these potential sources of bias for the true high school graduation rate. A sub-sample of the Census, the Integrated Public Use Microdata Series (IPUMS), contains more detailed education and demographic information than the CPS for both a 1 percent and 5 percent representative sample of the entire U.S. resident population. It is a useful tool for examining potential sources of bias in CPS-based estimates because it does not suffer from many of the disadvantages of the CPS. First, its universe is more inclusive than that of the CPS because it samples both institutional and military populations. Second, coverage rates are significantly higher in the Census than in the CPS. Finally, the Census began asking immigration questions long before the CPS did so. Immigrants who did not attend U.S. schools can be identified and excluded from the calculation of the graduation rate starting with the 1970 data.
For our purposes, Census data have two important drawbacks. In contrast to the CPS supplements that are available on an annual basis, Census data are only available every ten years. In addition, the Census questionnaire does not distinguish between GED recipients and regular high school graduates. However, using data from the GED testing service and a method similar to that used by Laird et al. , we are able to estimate the total number of GED recipients in each survey year for a given age range and deduct them from the total number of people reporting high school completion in the Census data. The estimated numbers of GED recipients using this method are in very close agreement with independent estimates obtained from survey data and are well within sampling error.10 We employ these survey data sources to obtain estimates for the distribution of GED recipients by gender and race/ethnicity in each Census year.
Contrary to the claim of Mishel and Roy , we do not find that the status completion rate based on the CPS provides a reasonable assessment of the graduation rate. It suffers from a number of sources of significant bias for the high school graduation rate and distorts trends both within and across groups.
Mishel and Roy  make calculations similar to the ones made in this paper. However, they do not simultaneously correct for all of the biases or fully account for GED recipients in the Census data. When these adjustments are made, we find that the two largest sources of bias are inclusion of GED recipients as graduates and a form of response bias to the CPS education question. Low sample coverage of the CPS is empirically unimportant. Bias from the CPS exclusion of military personnel is negligible. The exclusion of prisoners plays only a small role overall, but is important when computing race and gender differentials in graduation rates. We next discuss each of these points in detail and the effect of accounting for them on graduation rate estimates.11
The GED began as a small scale program designed to exam-certify veterans who interrupted their high school training to serve in the armed forces during World War II. Quinn  documents how the GED program has shifted from its original mission of certifying older veterans to become a substitute for high school graduation among school-age youth. Over 700,000 high school dropouts attempt to certify as “high school equivalents” each year through the GED program and over 65 percent of test takers are under the age of twenty-four.12 In 1960, only 2 percent of all new high school credentials were awarded through equivalency exams in the United States. Of all new high school credentials issued in the U.S. each year, currently 15 percent are obtained through GED certification.13
GEDs, on average, earn at the rate of dropouts. However, the GED is still generally accepted as the equivalent of a high school diploma for college admissions to many institutions and for eligibility to participate in job training and financial aid programs. Historically, GED recipients have also been counted as high school graduates in many official federal, state, and local education statistics.
Some states even issue state-accredited high school diplomas on the basis of GED test scores.14 In New Jersey, for example, an individual can mail in GED test scores that meet the state's GED score requirement to qualify for a state-endorsed high school diploma. Candidates do not even need to reside in the state in order to qualify.15 These credentials are then included in official state diploma counts issued by NCES and in calculations of state graduation rates.16 In fact, in some years, administrative data show that diplomas issued in New Jersey are greater than the total number of students enrolled in the 12th grade. Unsurprisingly, New Jersey is estimated to have one of the highest graduation rates in the country (see Greene  and Swanson ).17
Another troubling aspect of the GED program is its disproportionate use by minorities. The GED program conceals serious problems in minority educational attainment rates.18 Historical trends in the status completion rate suggest that minorities are closing the secondary schooling gap with majorities (see Figure I). However, black male high school completers are almost twice as likely as white males to possess a GED certificate (Cameron and Heckman ) and a substantial proportion of these GED credentials are produced in prisons. Prison GED recipients now account for over 10 percent of all GED certificates issued in the U.S. each year.19 For black males, 22 percent of all GED credentials are produced by the prison system each year compared to 5 percent and 8 percent for white and Hispanic males, respectively.20 Prison GED credentials have very low economic returns (Tyler and Kling ). It is of great concern that measures that do not count these alternative credentials (obtained in prison or otherwise) as graduates still show large gaps between minority and majority groups as well as no convergence over the past 35 years.
Counting GED recipients as dropouts has a substantial impact on the estimated graduation rate (Table I(a)).21 This table presents the change in the estimated graduation rate in the 2000 Census data under various sample restrictions and assumptions commonly made in the literature. All categories are mutually exclusive so that an individual is only counted once.22
Table I (a)
Increase in the Estimated Graduation Rate Using Census 2000 Data under Various Assumptions
The overall graduation rate is increased by 7.4 percentage points when GED recipients are counted as high school graduates. The increase is greater for males than for females, in part due to the high rate of GED certification among males in prison. Excluding GED recipients lowers black graduation rates more for blacks than for whites. The overall black rate falls by roughly 2 percentage points more than the overall white rate after excluding GED recipients.23 Due in large part to the disproportionate number of black males obtaining GED credentials in prison, the greatest bias occurs in the black male estimates—more than 10 percentage points.
There has been an explosion in the growth of the incarcerated population since the early 1980s.24 In 2002, the total incarcerated population exceeded 2 million people.25 Minority males, especially young black males, have been disproportionately affected by tougher anti-crime measures. Nearly one out of every ten black males age 18−24 is now incarcerated. It is estimated that more than one-third of all black male high school dropouts ages 20−35 were in prison on an average day in the late 1990s – a higher proportion than is found in paid employment (Western and Pettit ).
Educational attainment among the prison population is extremely low.26 Of all prisoners, seventy-eight percent are uncertified high school dropouts or GED recipients. Furthermore, 56 percent of the incarcerated high school completers obtain that status through GED certification.27
Excluding the prison population has only a small effect on the overall graduation rate, increasing it by slightly more than 1 percentage point (Table I(a)), but has more substantial impacts on race and gender comparisons.28 Overall male rates are biased upward by 1.8 points when prisoners are excluded while overall female rates are virtually unchanged. Excluding the prison population decreases the estimated black-white gap in high school graduation rates by 2.4 percentage points. This change is even greater when the sample is limited to males. The black-white male gap is biased downward by nearly 4.6 points when the prison population is excluded, as it is in computing status completion rates based on CPS data.
These calculations are potentially very sensitive to the order in which they are performed. Table I(b) performs the calculations in a different order, reversing the roles of GED and prison. The numbers change somewhat. The black-white graduation gap closes by 2% (instead of 2.4%) when prisoners are excluded. For males the gap is lowered by 3.7% (instead of 4.6%). Counting GEDs as high school graduates reduces the black-white graduation gap by only .7% (compared to 1.6% in Table I(a)) and by 2.3% (compared to 2.4% in Table I(a)) for females. These calculations demonstrate the importance of incarceration in distorting the statistics on black graduation rates. Tables I(c)-I(f) displayed in Web Appendix S.0 show results from other orders of decomposition. The conclusions of Tables I(a)-I(b) are generally robust to the alternative decompositions.
Table I (b)
Increase in the Estimated Graduation Rate Using 2000 Census Data under Various Assumptions
In 2000, 91 percent of military recruits across all services were high school graduates; 7.4 percent were GED recipients, and only 1.5 percent were uncertified dropouts.29 Most military personnel are high school graduates and excluding them could potentially bias the estimated high school graduation rate downward.30 However, because the military is a relatively small segment of the population, excluding the military population from the CPS has only a minor effect on the overall graduation rate. The net effect of excluding armed forces personnel is one-tenth of a percentage point overall (Table I(a)). The estimates by race are also largely unchanged due to similar high school attainment rates among enlisted whites and minorities.
Recent immigrants who never attended high school in the United States are a growing fraction of CPS-sampled 18-to-24-year-olds. Hispanics account for most of this group. Census data show that almost half of Hispanics in this age group immigrated within the last ten years. These recent Hispanic immigrants are primarily low-skilled Mexican workers who have significantly lower high school attainment rates than U.S.-educated Hispanics. The large influx of immigrants into the United States in the past two decades imparts a serious bias to both levels and trends.31 A meaningful evaluation of the performance of the U.S. educational system should not include people who never attended U.S. schools or those who did so only briefly.
To examine the effect of immigration on the graduation rate estimates, we exclude from the 20−24 year old sample immigrants who entered the U.S. within the past 10 years. Including immigrants biases the overall high school graduation rate downward by 2.6 points (Table I(a)). The largest bias is observed for Hispanic attainment rates—nearly 11 percentage points overall. Hispanic male rates are more strongly affected than Hispanic female rates by the inclusion of immigrants. In the next section we show that the trends in Hispanic graduation rates are also strongly affected by this bias. The migration of workers with low levels of education has increased substantially over the past 40 years.
Low Coverage and Response Bias
Low coverage rates are a potential source of bias in CPS data. This source of bias is distinct from the CPS exclusion of the non-civilian and institutional populations. Coverage is usually discussed in terms of the coverage ratio, defined as the population estimate for a given group divided by the known target population size for that group based on an independent data source. Overall, the coverage ratio of the CPS is .92. This means that the CPS population estimate for the civilian non-institutional population is 92 percent that of the Census count. Coverage rates vary substantially by age and race.32 Young minority males are the least likely to be sampled. For example, the coverage ratio for black males ages 20−29 is only .66 in the CPS. In contrast, the coverage ratio for non-black males in this age group is .85. CPS sample weights are adjusted by race and sex to account for this known undercoverage in an attempt to eliminate potential bias.33 However, Sum et al.  argue that low coverage leads to an upward bias in CPS-based graduation rates, because those who are missed by the survey likely have lower educational attainments than the sampled population.
Using the Census data, we can partially assess the role of incomplete coverage in estimating graduation rates since Census coverage rates are much higher than CPS coverage. A concerted effort is made by the Census Bureau to obtain complete counts of the entire resident population every ten years including the military and institutional populations. As a result, the overall coverage ratio is .98.34 Census coverage of minorities greatly exceeds that in the CPS data. The coverage ratio for black males and females age 20−29 in the Census data is .91 and .96, respectively. In addition, the inclusion of the incarcerated and military personnel in the Census data further mitigates the potential bias of CPS-based estimates.
To assess the role of undercoverage in biasing CPS-based estimates of high school graduation rates, we compare the educational attainment distributions in the CPS March 2000 demographic supplement with those found in the 2000 Census data for the civilian non-institutional population.35 The CPS March and Census educational attainment question are essentially the same. Due to the similarity in the sample designs and timeframes, the estimates should be closely aligned in the two surveys.36
The overall population totals for 20−24 year olds in the civilian non-institutional population are nearly identical in the two data sources. The CPS underestimates those with low educational attainments and more so for minority groups (Table II). The CPS overestimates the fraction of high school completers (both GEDs and high school graduates) in the 20- to 24-year-old population relative to the Census and undercounts uncertified dropouts. As a result, the overall completion rate based on the CPS data is nearly 2 percentage points higher than the Census and this difference is even greater for minority groups.
CPS March vs. Census Difference in % of Population Reporting a Given Education Level, Ages 20−24 in 2000
A closer examination of the distributions of educational responses in the two data sources reveals that the data align across all educational categories with the exception of two.37 The CPS substantially undercounts dropouts who completed 12th grade, but received no diploma and overestimates the percentage of high school graduates who did not attend college relative to the Census (Table II). The difference between the two data sources in the number of dropouts reporting all other grade levels (completing 11th grade or less) is negligible for all groups with the exception of black males.
Given that the CPS underestimates the number of dropouts in only one educational category, it is unlikely that low sample coverage is the source of the discrepancy. If the discrepancy in the number of dropouts is due to undercoverage, we would expect a more uniform pattern of undercounting across all of the lower education categories (11th grade and less).
A number of Census Bureau reports have discussed errors that arise in measuring the 12th grade no-diploma category. Singer and Ennis  show that the 12th grade no-diploma responses showed the highest rates of inconsistency when respondents are reinterviewed. Scanniello  reports similar discrepancies when comparing educational responses in the CPS March against the Census-conducted American Community Survey data (ACS). The ACS is a new survey similar in sample design, mode of administration and coverage to the IPUMS.
Scanniello suggests that the discrepancy in the 12th grade, no-diploma category likely results from differences in survey administration. Census Bureau surveys are primarily administered through a mail questionnaire while the CPS is primarily conducted through telephone interviews. It appears that respondents are able to more accurately distinguish between the two categories in the Census and ACS data for two reasons. First, respondents see the available choices when responding to the paper-based ACS and Census surveys whereas the choices are read to them over the phone in the CPS. This may be particularly important for getting respondents to distinguish between completing 12th grade with no degree and finishing with a diploma. Second, the ACS and Census instrument allows each member of the household to fill out questions that pertain to them rather than have one person respond for the entire household as is the case in the CPS. CPS proxy respondents are unlikely to be able to distinguish between someone who completed 12th grade with or without a diploma.38
The final two rows of Table II summarize our findings by estimating the total bias in the CPS design as well as the total bias in the CPS-based status completion rate by race. The CPS design bias is calculated as the total bias resulting from the undercount of dropouts and the exclusion of prisoners and military personnel from the sample. This source of bias results in the CPS overstating high school completion by 3 points overall and by over 5 points for blacks. The total bias calculation adds the bias resulting from assuming that GED recipients are high school graduates to the previous survey design bias totals. The 2000 CPS status completion rate overstates the graduation rate by 8 percent overall and over 15 points for blacks. In 2000, the bias in using the status completion rate as an estimate of the Hispanic high school graduation rate in 2000 is very small. The inclusion of recent immigrants offsets the other sources of bias.39
B. Common Core of Data Estimates
The Common Core of Data (CCD) are collected on an annual basis from state departments of education. They report the number of students enrolled in each grade level as well as the number of high school diplomas issued. From these data, an approximate cohort high school graduation rate can be calculated by dividing the number of diplomas issued in a given year by the number of entering ninth-grade grade students four years earlier. Some measures adjust the enrollment and diploma counts for migration between states while others average one or more years of enrollment data to form a smoothed estimate of the entering freshman class. This data source has become more valuable and widely used today because it is the basis for estimates at the state, district and even school level, as required by NCLB. Most recent national graduation rate estimates based on CCD data are between 68−70 percent – substantially lower than those reported in the previous section based on household survey data (see Greene , Swanson and Chaplin  and Warren and Halpern-Manners ).
The primary reason for this discrepancy is due to the use of 9th grade enrollments in the denominator (Miao and Haney  and Mishel and Roy ).40 The CCD data do not report estimates of the number of entering ninth graders. Instead they report the total ninth-grade enrollment in each year. Upper level students are typically held back at the 9th grade. This causes CCD estimators that use 9th grade enrollments to be biased downward because they double count the retained students in the denominator.
To gauge the magnitude of this bias, we proxy grade retention by calculating the ratio of 9th grade enrollments to 8th grade enrollments in the previous year expressed in percentage terms for public schools (see Figure II). In the mid-1950s, fall 9th-grade enrollment counts were nearly identical to the previous year's fall eighth-grade class size. By 2000, they were over 13 percent larger. Ninth-grade retention bias is even greater for minorities than for whites. Minority 9th grade enrollments are often 20−26 percent greater than the previous year's 8th enrollment count, as opposed to only 6−10 percent for whites. This severely biases estimated minority graduation rates downward relative to those of whites if one uses 9th grade enrollment in the denominator. The claim that only 50 percent of minorities graduate high school is based on this biased estimator.41
Percent of Ninth Grade Enrollments Relative to Eigth Grade Enrollments in the Previous Year Based on Public School Enrollment Counts, 1954 to 2005, NCES
To avoid this problem, we use the previous year's eighth-grade enrollments to proxy for the entering ninth-grade class. This estimator—first used by Miao and Haney —avoids the problem of ninth-grade retentions and produces estimates that are consistent with Census and all other data sources. Figure III plots the estimated trends in public school graduation based on this estimator for the graduating classes of 1960−2005. By this measure, the overall U.S. graduation rate steadily increased throughout the early 1960s and peaked in the early 1970s. It then steadily declined from this point until the early 1980s. Graduation remained stagnant throughout the 1980s until declining sharply during the early 1990s only to rebound again after 2000. However, even with this recent surge, the U.S. high school graduation rate today is still below the peak attained during the early 1970s.
Public HS Graduation Rates by Race Using 8th and 9th Grade Estimators: 1960−2005
The bias for minority graduation rates is substantial. In 1960, the bias associated with dividing by the 9th grade enrollment rather than 8th grade enrollment was negligible. In recent years, the difference between the two estimators is as large as 9 points overall and 14 points for minorities. For the 2000 Census cohort, the 9th grade estimator yields an overall graduation rate of only 68 percent. This is very different from the Census estimate of 77 percent. Estimated minority graduation rates miss the mark completely. The Hispanic rate is 52 percent, while the black rate is 50 percent. Both estimates differ substantially from those obtained from both the Census and the eighth grade-based measure.42
Comparisons between the CCD and Census micro-data estimates are in close agreement. Assuming that students graduate at age 18, comparing the CCD estimates for the graduating classes of 1994−1998 to the 2000 Census estimates for those ages 20 to 24, we find that the two data sources agree. The overall Census estimate for these graduating cohorts is 77.1 percent while the CCD estimate is 76.6 percent. The predicted rates for whites, blacks and Hispanics in the Census are 81 percent, 66 percent, and 63 percent, respectively. Using CCD data, we estimate rates of 80.5 percent, 62 percent, and 65 percent, respectively.43
While the Census and 8th grade estimator generally agree in levels and exhibit the same overall trends in graduation over time, the 8th grade estimator consistently produces slightly lower overall estimates (∼ 1 percent) than the Census and longitudinal data sources over time. For minorities, the disparity between the two sources is greater – generally 3 to 5 points. The discrepancy likely arises from the inclusion of more types of diplomas in the Census estimator. Many post-high school training and education programs such as Job Corps, Adult Basic Education and Adult Secondary Education also issue state-endorsed regular high school diplomas that are not counted in the CCD school-based data. The diplomas issued by these programs are relatively small overall since their primary focus is on GED certification.44 However, these post-schooling diplomas are more important for estimating minority rates since enrollment in these programs draws heavily from minority populations. CCD-based measures provide the best available indicator of the performance of American public schools while the Census and other survey data are more indicative of final attainment.
More U.S. high school students are staying in school, according to newly released data from the Census Bureau, as the national dropout rate reached a record low last year. Just 7% of the nation’s 18-to-24 year olds had dropped out of high school, continuing a steady decline in the nation’s dropout rate since 2000, when 12% of youth were dropouts.
The decline in the national dropout rate has been driven, in part, by substantially fewer Hispanic and black youth dropping out of school (the non-Hispanic white dropout rate has not fallen as sharply). Although Hispanics still have the highest dropout rate among all major racial and ethnic groups, it reached a record-low of 14% in 2013, compared with 32% of Hispanic 18- to 24-year-olds who were dropouts in 2000.
The new data show significant progress over the past decade at other measures of educational attainment among Hispanic youth: Not only are fewer dropping out of high school, but more are finishing high school and attending college. The only exception is that Hispanics continue to substantially trail white youth in obtaining bachelor’s degrees.
The decline in the size of the Hispanic dropout population has been particularly noteworthy because it’s happened at the same time that the Hispanic youth population is growing. The number of Hispanic 18- to 24-year-old dropouts peaked at 1.5 million in 2001 and fell to 889,000 by 2013, even though the size of the Hispanic youth population has grown by more than 50% since 2000. The last time the Census Bureau counted fewer than 900,000 Hispanic dropouts was in 1987.
Aside from the Great Recession, the trend in more Hispanic youth staying in school is occurring against the backdrop of diminishing job opportunities for less-educated workers, including less-educated Hispanic workers. Hispanic students and their families may be responding to the rising returns to a college education by staying in school.
Indeed, census data show that Hispanics have reached a record high school completion rate.
Among Hispanic 18- to 24-year-olds, 79% had completed high school compared with 60% who did so in 2000. High school completion rates have also been rising for other racial and ethnic groups, but their rates were not at record highs in 2013.
For Hispanics, education has long been a top issue; in Pew Research surveys, Hispanics often rank education as one of the most important issues, along with health care and immigration. Hispanics also made up 25% of the nation’s public school students in 2013, with that share projected to rise to 30% by 2022.
Hispanics have also made progress in college enrollment at two- and four-year schools. Among college students ages 18 to 24, Hispanics accounted for 18% of college enrollment in 2013, up from 12% as recently as 2009, according to the new census data.
But young Hispanics still lag behind in earning four-year college degrees. Hispanic students account for just 9% of young adults (ages 25 to 29) with a bachelor’s degree. By comparison, whites account for about 58% of students ages 18 to 24 enrolled in college and 69% of young adults with a bachelor’s degree.
The dropout rate for black youth also was at a record low in 2013 (8%) and has fallen by nearly half since 2000 (15%). Blacks comprised 16% of the nation’s public school students in 2013, with that share projected to fall to 15% by 2022.
Among non-Hispanic white youth, the dropout rate has also declined since 2000 to 5% in 2013.
Asian youth continue to be the major racial group with the lowest high school dropout rate (4% in 2013), but it was not at a record low last year.
Topics: Education, College
Richard Fry is a senior researcher focusing on economics and education at Pew Research Center.