Budget cuts have caused increases in class size in states across the nation in recent years. Between 2009 and 2010, the pupil-teacher ratio in the U.S. increased by more than half a student for the first time since the Great Depression. The nationwide increase is quite small, but some states have experienced larger changes than others. A notable outlier is California, where the pupil-teacher ratio increased by more than 4 students between 2009 and 2010, an increase of more than 20 percent.
Times of fiscal austerity renew debates about the best way to spend limited educational resources. Class size is at the center of these debates because the size of the classes in which students are educated is one of the most important drivers of educational costs. Smaller classes mean that more teachers must be hired and more classrooms built. Conversely, allowing class sizes to increase can be a way to absorb budget cuts without cutting other programs such as athletics and the arts.
Research on the effects of class size is mixed. Most studies find at least some evidence that smaller classes have positive effects, but the size of these benefits is inconsistent across studies and often small. The substantial costs of reducing class size coupled with these modest benefits implies that many school systems in the U.S. have overinvested in class-size reduction and that increasing class size in some situations may represent a budget-cutting strategy that minimizes harm to students.
Allowing modest increases in class size may make good policy, but it is treacherous politics. Parents want smaller classes for their children and teachers prefer fewer students in their classes. A 2007 survey of the American public found that 77 percent of respondents, and 81 percent of public school employees, preferred spending educational dollars on decreasing class size rather than increasing teacher salaries.
The direct tradeoff between class size and teacher salary comes directly from the rules of arithmetic. For any given level of funding, schools can either hire more teachers at lower salaries to teach smaller classes or fewer teachers at higher salaries to teach larger salaries. For example, a school with 100 fourth-grade students and a $250,000 budget for salaries could pay five teachers $50,000 each to lead classes of 20 students or four teachers $62,500 each to instruct classes of 25 students.
Parents, teachers, and the general public may not understand how significant these tradeoffs are. In the abstract, decreasing class size may seem more desirable than increasing teacher salaries, but what about comparing specific class size and salary changes that have the same cost? Two recent surveys asked exactly that question. A 2006 survey of Washington teachers found that 83 percent preferred a $5,000 raise to a two-student reduction in class size.
More recently, the journal Education Next and Harvard’s Program on Education Policy and Governance (PEPG) asked a nationally representative group of Americans whether they thought it was better to increase teacher salaries by $10,000 or decrease class size by three students. Forty-four percent of respondents said they preferred the reduction in class size, 28 percent preferred the salary increase, and the remaining 29 percent had no opinion either way. Class size was still the preferred policy, but by a much narrower margin than in the 2007 survey that didn’t word the question in terms of equally costly alternatives. Parents expressed similar preferences to the general public, but teachers were about evenly split between the salary increase and the class size decrease.
Source: 2011 Education Next-PEPG Survey.
These data indicate that almost half of teachers do not think smaller classes are worth the cost (relative to the alternative of a salary increase), and a substantial minority of parents hold the same view. For teachers and the unions that represent them in the political process, it may well be the case that increases in class size are preferable to an alternative of reductions in salary or benefits. The class-size reduction policies that were popular in recent decades were enacted in a time of steadily increasing educational spending. Smaller classes were likely a way to marshal popular support for increased spending when the dollars were available.
For parents, class size still holds a decisive edge over teacher salaries, even when the relative costs are made clear. But this isn’t the only tradeoff that schools are facing. Allowing class size to increase may be the only way for some schools to avoid cuts to other popular programs such as music, art, athletics, and other extracurricular activities. More parents might choose these programs over class size in a head-to-head comparison.
In the coming years, states will continue to face hard choices about how to spend limited educational dollars. Accepting modestly larger classes may be the best way to absorb budget cuts in some contexts, especially in states that already have quite small classes. The politics of increasing class size would seem to be challenging given the popularity of small classes with teachers and parents. But survey data suggest that attitudes change dramatically when the tradeoffs are put in terms anyone can understand: dollars and cents.
 A notable exception to this rule occurs in secondary schools, where teaching load—the number of classes assigned to a teacher—is an important third variable (I discuss this issue further here).