The Push for Smaller Classes: Is it Worth the Investment?

E-newsletter Issue #75 | August 04, 2011

Ask a group of parents and teachers if they prefer classes with fewer pupils for their children and students and it’s likely the response will be overwhelmingly, if not unanimously, “yes!” Ask education researchers, however, and it’s likely the responses will be more muddled. 

Multiple studies tracking the relationship between class size and student achievement have produced contradictory conclusions. Consequently, policymakers are left without definitive research that clearly shows whether spending more money to reduce class size will result in higher student achievement scores.

The Case For Smaller Classes

During the 2010 election, Florida voters sent their elected leaders a mixed message. On one hand, they elected a conservative Republican legislature and governor running on a platform of reining in government spending. On the other hand, they rejected Amendment 8, which would have eased class size restrictions put in place by a 2002 ballot initiative.  The defeat of Amendment 8 will cost Florida taxpayers $40 billion over the next decade, according to the Florida Education Finance Program.

According to the National Center for Education Statistics, the national ratio of students to teachers declined from 17.6 in 1990 to 15.8 in 2008. That number is artificially low, however, because it includes special education and other specialized teachers who typically have much smaller classes. The U.S. Department of Education estimates the current average class size in departmental instruction—such as English, science, math and social studies —is closer to 25 students per teacher.

Despite the expense of employing more teachers to reduce pupil-teacher ratios, a study by Alan Krueger published in The Economic Journal concludes reducing class sizes from 22 to 15 in grades K-3 actually results in a $2 return on every $1 spent. That calculation is based on the assumption that the smaller classes will result in increased student achievement and increased earnings later in life.

Another study, this one conducted by the Health and Education Research Operative Services, found that when compared to average-sized classes, students in smaller classes in the early years eventually take more advanced courses in high school and are more likely to graduate in the top 10 percent of their class. Krueger and Diane Whitmore, in another study, found that African-American students who attended small classes in the early elementary years were more likely to take the SAT and ACT in high school. This study estimated that smaller elementary class sizes alone could reduce the black/white gap in SAT and ACT participation by 60 percent.

The National Education Association also contends reducing the pupil-teacher ratio helps in the early identification of learning disabilities and leads to fewer special education placements in later grades, improves high school graduation rates, and results in fewer incarcerations and improved student behavior.

The most highly regarded study concluding a positive relationship between smaller classes and student achievement is Project STAR, which began in 1984 and tracked more than 7,000 students in 79 Tennessee schools. In 1999,  researchers reported the students who had been randomly placed in small classes in grades K-3 had better high school graduation rates, higher grade point averages and were more likely to pursue postsecondary education.

Smaller Classes Not The Answer

Many education policy experts and researchers have questioned the validity of these studies. Other research shows no correlation between class size and student achievement.

A study conducted by Matthew Chingos, a research fellow at Harvard University’s Program on Education Policy and Governance, analyzed reading and math test scores for all Florida students in grades four through eight between 2001 and 2007. 

Following a ballot initiative that resulted in class-size caps in Florida, Chingos evaluated the impact Florida’s policy had on student achievement. He found students attending schools in districts that were required to reduce class size did no better on state assessments than students in schools with higher pupil-teacher ratios. His study also showed no significant relationship between class size, absenteeism and behavior.

Other researchers also have concluded class size reduction does not have a significant effect on achievement. One such study examined trend data from the 1950s to 1986 and did not find any consistent relationship between class size and standardized test scores. In the U.S. Department of Education report, “Class size and public policy: Politics and panacea,” author Tom Tomlinson concluded existing research did not justify a policy to reduce class size in view of the costs involved.

Similarly, a review of research published in Educational Evaluation and Policy Analysis concluded, “… A system-wide class reduction policy would produce only modest gains in student achievement and incur an unjustifiably high cost.”

Class Size & Policy

According to the Education Commission of the States, 25 states have policies requiring class-size reductions to a level below 22 students per classroom. The vast majority of these policies target students in elementary grades, particularly K-3. 

In a speech in November 2010, U.S. Education Secretary Arne Duncan called for class size flexibility. “In our blueprint for reauthorizing the Elementary and Secondary Education Act, we support shifting away from class-size based reduction that is not evidence-based. It might be that districts would vary class sizes by the subject matter or the skill of the teacher, or that part-time staff could be leveraged to lower class size during critical reading blocks,” he said.


Reducing class size is widely considered one of the most expensive education reform measures a state can take. While conventional wisdom would seem to indicate that smaller classes are beneficial, legislators and other policymakers will likely need to be convinced the additional funds they could spend in other ways will be worth the cost. At this time, the evidence is murky at best, contradictory at worst, making it difficult for policymakers to make well-informed decisions whether to spend money to continue strict caps on pupil-teacher ratios.            

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