A growing number of scholars and political commentators have concluded that the U.S. public school system is flawed, and that it can only be corrected by fundamental changes in the institutions that govern education. Chubb and Moe (1990, p. 3), for example, argue that the "existing [educational] institutions cannot solve the problem, because they are the problem." Widespread belief that the current educational system is flawed, rather than any concrete or systematic evidence indicating that an alternative system performs better than the current one, has motivated frequent calls for radical "institutional reforms" of schools.
The view that the U.S. school system has failed, or is "broken," is commonly supported by three arguments: (1) there has been a steady decline in the performance of American students on standardized tests, (2) American children perform worse on international comparisons than foreign children, and (3) the existing system fails to convert school resources (such as smaller classes) into school outputs (such as better test performance).(1)
This paper reassesses the claim that American schools are broken. The first section examines trends in National Assessment of Educational Progress (NAEP) test scores, and the relationship between average test score performance and school resources on an aggregate level. Although the aggregate data show a surprisingly strong, positive relationship between educational spending and student achievement, one should be cautious about drawing any causal inference from such a relationship because of changes in the composition of students over time and changes in the focus of educational spending. More convincing evidence comes from the randomized experiment on class size, which I describe in the subsequent section. Next, I infer the influence of schooling on student performance by considering gains in student achievement by socioeconomic status (SES) during the school year and during the summer months. The paper's final section summarizes evidence on the increasing economic rewards associated with completing high school.
The main conclusion from this review is that the widely held belief that American schools have failed--that they are performing worse today than they have in the past, that a high school degree is no longer valuable, and that additional resources yield no benefits in the current system--is not supported by the evidence. The evidence suggests that the perceived crisis in education has been greatly exaggerated, if indeed there is a crisis at all. Nonetheless, major changes in U.S. schooling might produce more desirable results. However, it would not be prudent to radically restructure the U.S. education system out of misplaced frustration that the current system has failed miserably or out of an unsupported presumption that progress cannot be made in the context of the existing system. In light of these findings, the conclusion offers incremental proposals to improve our schools.
WHAT DO THE AGGREGATE ACHIEVEMENT TEST DATA TELL US?
AGGREGATE TIME TRENDS
Concern over the deteriorating performance of U.S. students is often based on time-series trends in the Scholastic Aptitude Test (SAT). For example, Chubb and Moe (1990, pp. 7-8) write, "the single most important symbol of the underlying problem came to be the monotonic decline, from the mid-1960s through 1980, in the scores of high school students on the national Scholastic Aptitude Test, or SAT." The emphasis on the average SAT score is odd because the exam is not designed to measure students' current levels of acquired skills, but instead their potential to perform well in college. Even more important, the students who take the SAT are a self-selected lot, and the selection has changed dramatically over time. As a wider segment of American students has attended college, the percentage of high school seniors taking the exam has increased. This increase has been particularly strong among students who rank in the bottom half of their high school class (see Berliner and Biddle ). Because the composition of students taking the SAT has changed over time, the College Entrance Examination Board, which publishes the test, has repeatedly warned against inferring trends in school or student performance from the SAT (see, for example, College Entrance Examination Board ).
To the extent that one can correct for the changing mix of students who take the SAT, there is little cause for alarm. For example, Berliner and Biddle (p. 22) show that between 1976 and 1993, the average SAT score has gone up for every demographic group except whites, and it declined only slightly for whites. The authors (p. 32) also summarize evidence that shows an upward trend in the 1980s in the California Achievement Test (CAT), the Stanford Achievement Test, the Comprehensive Test of Basic Skills, and other commercial tests. There is little support in these data for the claim made by the National Commission on Excellence in Education (1984, p. 8) that "average achievement of high school students on most standardized tests is now lower than 26 years ago when Sputnik was launched."
Most analysts probably agree that the NAEP exam provides a more meaningful assessment of trends in student performance than the SAT. Like the SAT, the NAEP is conducted by the Educational Testing Service. But unlike the SAT, the exam is administered to a representative sample of students and is intended to assess progress on basic math, reading, and science skills. The NAEP exam has been administered to nine-, thirteen-, and seventeen-year-olds in selected years since 1970. There are a total of nine time trends that can be analyzed with the NAEP data. Chart 1 presents the average NAEP exam scores for each year, after age and subject main effects have been removed.(2) For most of the subjects and age groups, the NAEP data display a modest upward time trend after an initial dip in the early 1970s. Indeed, the correlation between the average NAEP score and time (that is, the year in which the test was given) is positive for eight of the nine age-by-subject cases, and it is statistically significant at the 10 percent level for seven of the nine cases. The median of these nine linear trends indicates that test scores are rising by .06 standard deviation per decade.(3) It is also possible that the unadjusted NAEP data understate the upward trend in student performance because the composition of students has changed over time. In particular, the rising proportion of students who are immigrants and minorities, and raised in poverty and by single parents, might be expected to lower average test scores over time.(4)
Chart 2 displays trends in average NAEP mathematics test scores for seventeen-year-old black students and for all students who live in disadvantaged urban communities.(5) The scores are expressed as deviations from the 1973 overall NAEP score, divided by the 1996 cross-sectional standard deviation. Perhaps surprisingly, the chart shows that the most disadvantaged students have made the greatest gains. The gap in math scores between students in disadvantaged communities and all communities narrowed by approximately one-half of one standard deviation in the 1980s. Moreover, between the early 1970s and 1990, the black-white NAEP mathematics test-score gap for seventeen-year-olds decreased by nearly half, although the gap …