The larger a class is, the more student misbehavior reduces teaching effectiveness, suggests research by Edward Lazear, published in the Quarterly Journal of Economics. If student behavior is good-as in Japan, and in private schools, which don't tolerate misbehavior-schools can increase class size without sacrificing achievement, but class sizes should be decreased in schools where misbehavior is common. For a summary of the research, see "Student Misbehavior Solves Classroom Size Mystery," Daily Policy Digest, National Center for Policy Analysis, August 8, 2002.
