Experimental Estimates of Education Production Functions-英文文献.pdf

EXPERIMENTAL ESTIMATES OF EDUCATION PRODUCTION FUNCTIONS* ALAN B. KRUEGER This paper analyzes data on 11,600 students and their teachers who were randomly assigned to different size classes from kindergarten through third grade. Statistical methods are used to adjust for nonrandom attrition and transitions between classes. The main conclusions are (1) on average, performance on standardized tests increases by four percentile points the rst year students attend small classes; (2) the test score advantage of students in small classes expands by about one percentile point per year in subsequent years; (3) teacher aides and measured teacher characteristics have little effect; (4) class size has a larger effect for minority students and those on free lunch; (5) Hawthorne effects were unlikely. I. INTRODUCTION The large literature on the effect of school resources on student achievement generally nds ambiguous, conicting, and weak results. Even quantitative summaries of the literature tend to reach conicting conclusions. For example, based on the fact that most estimates of the effect of school inputs on student achievement are statistically insignicant, Hanushek [1986] con- cludes, ‘‘There appears to be no strong or systematic relationship between school expenditures and student performance.’’ By con- trast, Hedges et al. [1994] conduct a meta-analysis of (a subset of ) the studies enumerated by Hanushek and conclude, ‘‘the data are more consistent with a pattern that includes at least some positive relation between dollars spent on education and output, than with a pattern of no effects or negative effects.’’ Much of the uncertainty in the literature derives from the fact *