class size

Author
Abstract

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 non-random attrition and transitions between classes. The main conclusions are: (1)
on average, performance on standardized tests increases by 4 percentile points the first 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.

Year of Publication
1997
Number
379
Date Published
05/1997
Publication Language
eng
Citation Key
Quarterly Journal of Economics, Volume 114, Issue 2, May 1999
Krueger, A. (1997). Experimental Estimates of Education Production Functions. Retrieved from http://arks.princeton.edu/ark:/88435/dsp012v23vt38v (Original work published 05/1997AD)
Working Papers
Abstract

This paper provides a long-term follow-up of students who participated in the Tennessee STAR experiment. The Tennessee STAR experiment randomly assigned l 1,600 elementary school
students and their teachers to a small class, regular-size class or regular-size class with a teacher-
aide. The experiment began with the wave of students who entered kindergarten in 1985, and
lasted for four years. After third grade, all students returned to regular-size classes. We analyze
the effect of past attendance in a small class on standardized test scores through the eighth grade,
on whether students took the ACT or SAT college entrance exam, and on how they performed on
the ACT or SAT exam. The results suggest that attending a small class in the early grades is
associated with somewhat higher performance on standardized tests, and an increase in the
likelihood that students take a college-entrance exam, especially among minority students. Most
significantly, being assigned to a small class appears to have narrowed the black-white gap in
college-test taking by 54 percent.

Year of Publication
1999
Number
427
Date Published
10/1999
Publication Language
eng
Citation Key
Economic Journal, 111, (468) January 2001
Whitmore, D., & Krueger, A. (1999). The Effect of Attending a Small Class in the Early Grades on College-Test Taking and Middle School Test Results: Evidence from Project STAR. Retrieved from http://arks.princeton.edu/ark:/88435/dsp010v838058q (Original work published 10/1999AD)
Working Papers
Author
Abstract

This paper examines evidence on the effect of class size on student achievement. First, it is
shown that results of quantitative summaries of the literature, such as Hanushek (1997), depend
critically on whether studies are accorded equal weight. Hanushek summarizes 277 estimates
extracted from 59 published studies, and weights all estimates equally, which implicitly places
more weight on some studies than others. A small number of studies, which often present
estimates for several small subsamples of a larger sample, account for more than half of the
estimates. Studies from which relatively many estimates were extracted tend to find negative
effects of school resources, whereas the majority of studies from which relatively few estimates
were extracted tend to find positive effects. When all studies in Hanushek’s literature summary
are given equal weight, resources are systematically related to student achievement. In addition,
when studies are assigned weights in proportion to the “impact factor” of the journal in which
they were published -- a crude measure of journal quality -- class size is systematically related to
achievement. When studies are given weights in proportion to their number of estimates,
however, resources and achievement are not systematically related. It is argued that assigning
equal weights to studies, or weights according to quality, is preferable to assigning weights
according to the number of estimates extracted from the studies, because study quality is unlikely
to be related to the number of estimates taken from the study, and because researcher discretion
in selecting estimates is limited when studies are assigned equal weight.
Second, a cost-benefit analysis of class size reduction is performed. Results of the Tennessee
STAR class-size experiment suggest that the internal rate of return from reducing class size from
22 to 15 students is around 6 percent.

Year of Publication
2000
Number
447
Date Published
09/2000
Publication Language
eng
Citation Key
8295
Krueger, A. (2000). Economic Considerations and Class Size. Retrieved from http://arks.princeton.edu/ark:/88435/dsp019z902z86c (Original work published 09/2000AD)
Working Papers
Author
Abstract

Many argue schools that serve inner-city and rural children are in “crisis.” This paper
reviews the best available evidence on the effects of class size and school vouchers. Results from
the Tennessee STAR experiment suggest smaller class sizes improve achievement, particularly for
inner-city and minority children; results from the New York City voucher experiment and the
Milwaukee Parental Choice program suggest there may be small achievement gains in mathematics
for the African-American and Hispanic children who use vouchers. Although the reason of the
achievement gains is unknown, one candidate is the smaller class sizes in the private schools.

Year of Publication
2000
Number
440
Date Published
06/2000
Publication Language
eng
Citation Key
7871
Rouse, C. (2000). School Reform in the 21st Century: A Look at the Effect of Class Size and School Vouchers on the Academic Achievement of Minority Students. Retrieved from http://arks.princeton.edu/ark:/88435/dsp013n203z091 (Original work published 06/2000AD)
Working Papers
Author
Abstract

In this paper I review the existing evaluations of the effect of the Milwaukee Parental Choice
Program on student achievement. Two of the three existing papers report significant gains in math for the
choice students and two of the three studies report no significant effects in reading. I also extend the analysis
to compare the achievement of students in the choice schools to students in three different types of public
schools: regular attendance area schools, city-wide (or magnet) schools, and attendance area schools with
small class sizes and supplemental funding from the state of Wisconsin (“P-5” schools). The results suggest
that students in P-5 schools have similar math test score gains to those in the choice schools, and students
in the P-5 schools outperform students in the choice schools in reading. In contrast, students in the city-wide
schools score no differently than students in the regular attendance area schools in both math and reading.
Given that the pupil-teacher ratios in the P-5 and choice schools are significantly smaller than those in the
other public schools, one potential explanation for these results is that students perform well in schools with
smaller class sizes.

Year of Publication
1998
Number
396
Date Published
01/1998
Publication Language
eng
Citation Key
The Quarterly Journal of Economics, Vol. 113, No. 2, May, 1998
Rouse, C. (1998). Schools and Student Achievement: More Evidence From the Milwaukee Parental Choice Program. Retrieved from http://arks.princeton.edu/ark:/88435/dsp0141687h45w (Original work published 01/1998AD)
Working Papers
Abstract

Economists attempting to explain the widening of the black-white wage gap in the late 1970's by
differences in school quality have been faced the problem that recent data reveal virtually no gap in the
quality of schools attended by blacks and whites using a variety of measures. In this paper, we re-
examine racial differences in school quality. We begin by considering the effects of using the pupil-
teacher ratio, rather than the school's average class size, in an education production function since the
pupil-teacher ratio is a rough proxy, at best. Second, we consider the importance of using actual class
size rather than school-level measures of class size.
We find that while the pupil-teacher ratio and average class size are correlated, the pupil-teacher
ratio is systematically less than or equal to the average class size. Mathematically, part of the difference
is due to the intraschool allocation of teachers to classes. As a result, while the pupil-teacher ratio
suggests no black-white differences in class size, measures of the school's average class size suggest that
blacks are in larger classes. Further, the two measures result in differing estimates of the importance of
class size in an education production function. We also conclude that school level measures may obscure
important within-school variation in class size due to the small class sizes for compensatory education.
Since black students are more likely to be assigned to compensatory education classes, a kind of
aggregation bias results. We find that not only are blacks in schools with larger average class sizes, but
they are also in larger classes within schools, conditional on class type. The intraschool class size patterns
suggest that using within-school variation in education production functions is not a perfect solution to
aggregation problems because of non-random assignment of students to classes of differing sizes.
However, once the selection problem has been addressed, it appears that smaller classes at the eighth
grade lead to larger test score gains from eighth to tenth grade and that differences in class size can
explain approximately 15 percent of the black-white difference in educational achievement.

Year of Publication
1995
Number
344
Date Published
06/1995
Publication Language
eng
Citation Key
Journal of Urban Economics, Volume 50, 2001
Boozer, M., & Rouse, C. (1995). Intraschool Variation in Class Size: Patterns and Implications. Retrieved from http://arks.princeton.edu/ark:/88435/dsp01x059c733k (Original work published 06/1995AD)
Working Papers