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Press Release · June 25, 2002

Not All School Districts Benefit From Class Size Reduction

Smaller Classes Boost Test Scores in High Poverty Schools, Except in Los Angeles

SAN FRANCISCO, California, June 25, 2002 – Reducing class size has affected California’s six largest school districts differently, with possibly negative outcomes in one district, according to a study released today by the Public Policy Institute of California (PPIC). The study finds that students in the Los Angeles Unified School District (LAUSD) appear to benefit little – and some may even fare worse – in the smaller classes that resulted from the state’s 1996 class size reduction (CSR) legislation. At the same time, test score gains among students in the next five largest districts – Fresno, Long Beach, Oakland, San Diego, and San Francisco – are larger than gains in school districts throughout the state as a whole.

Unlike past state research, the study finds that, overall, smaller classes have a greater positive effect on students in low-income schools. Authors Christopher Jepsen, a PPIC research fellow, and Steven Rivkin, an associate professor of economics at Amherst College, analyze third grade test scores between 1997-1998 and 1999-2000. In Fresno, Long Beach, Oakland, San Diego, and San Francisco, test scores increased 14 percent in math and 9 percent in reading in schools with mostly low-income students, while schools with few low-income students saw less than a one percent increase in math scores and only a 6 percent increase in reading scores. The state as a whole followed a similar pattern, although the difference between low-income and other schools was less pronounced.

However, this pattern does not hold in Los Angeles where schools with predominantly low-income students saw slightly lower test scores after class size reduction. “Other conditions in Los Angeles’ high poverty schools may be counteracting the positive effect of smaller classes,” says Jepsen. “On the whole, CSR increased the number of inexperienced, uncertified teachers in the most at-risk schools as more senior teachers left to fill new openings in more affluent schools. This problem appears to have been much more severe in L.A.’s high poverty schools than in similar schools in other districts.”

The study also finds that unlike the other five largest districts, LAUSD schools with higher percentages of black students did much worse in math following class size reduction. In almost perfect contrast, math scores in mostly black schools in Los Angeles dropped nearly 15 percent after class sizes were reduced, while math scores in the other five districts rose nearly 15 percent in schools with similar racial makeup. The study, Class Size Reduction, Teacher Quality, and Academic Achievement in California Public Elementary Schools, suggests that this surprising finding could also be related to CSR having exacerbated the shortage of qualified, experienced teachers in the poorest LAUSD schools.

The Public Policy Institute of California is a private, nonprofit organization dedicated to improving public policy through objective, nonpartisan research on the economic, social, and political issues that affect the lives of Californians. The Institute was established in 1994 with an endowment from William R. Hewlett. David W. Lyon is President and CEO of PPIC.