Teachers wave at students as they drive away in a school bus on the last day of classes Wednesday June 6, 2012, …
On Friday, Mitt Romney said he opposed sending federal money to local governments to hire more public workers, including teachers.
Obama "wants to hire more government workers. He says we need more firemen, more policemen, more teachers. Did he not get the message of Wisconsin?" Romney asked, referring to the failed effort to recall Gov. Scott Walker, the Wisconsin Republican who ended collective bargaining for public workers. "The American people did. It's time for us to cut back on government and help the American people."
On Monday, Romney surrogate and former New Hampshire Gov. John Sununu defended Romney's comment, arguing that there are too many teachers in some parts of the country where the student population has decreased. "If there's fewer kids in the classroom, the taxpayers really do want to hear that there will be fewer teachers, absolutely. You've got a lot of places where that is happening," he said on MSNBC.
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Is Sununu right that some districts have too many teachers? And if there are too many teachers, is smaller class size—a policy that Romney firmly opposes—responsible for the bloat?
It is true that the growth of the number of teachers in American public and private schools overall has far outpaced the growth of the number of students over the past 20 years. According to recent research by University of Pennsylvania education professor Richard Ingersoll, the ranks of school teachers have grown 48 percent over the last two decades while the student population has grown only 19 percent. That's not counting teachers' aides, librarians, counselors or other administrative staff—just people who primarily teach in schools. (Private school teachers make up about 12 percent of the teaching force overall, and both private and public teacher numbers have grown faster than student enrollment from 1988 to 2008.)
But Ingersoll tells Yahoo News that shrinking class size is only a small part of why the teaching force has ballooned. The average elementary school class size has decreased by about 20 percent, which required hiring more teachers. But over the same period, secondary classrooms have stayed the same or grown in size, he says.
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In fact, as much as 20 percent of the growth in the teaching force can be explained by a big increase in the number of special education teachers. (Until a federal law passed in 1975, schools could turn away kids with disabilities. Now more than 6 million kids receive some kind of public school special education, and special education classes are about half the size of regular public school classrooms.) The number of high school math and science teachers grew by 75 percent, meanwhile, as high schools began requiring students to take three or four years of math or science instead of only two in order to graduate. Finally, the number of teachers in the "elementary enrichment" category—people who teach one specialized subject, like computer science or math, to elementary-age kids—grew by 111 percent.
The increase in the number of teachers, broken down by job title. (Ingersoll and Merrill/University of Pennsyl …
Ingersoll says that the number of English as a second language teachers has also skyrocketed, by 400 percent over the past 20 years.
Much of the teaching force growth, then, has been driven by federal mandates or factors outside the control of local districts, such as immigration levels or tougher graduation standards. Ingersoll says local and state budget cuts in recent years have slowed the growth. (Also, teacher shortages still exist in certain areas. These figures just represent the overall picture.)
Andrew Coulson, who directs the education center of the libertarian CATO think tank, says that the staff to student ratio at public schools has changed from 13.9 to 1 in 1970 to about 7.7 to 1 today. (Coulson's calculations take into account every employee at a school, not just teachers.) He said he's surprised that politicians would be willing to point out this growth, however.
"Not only are they right in saying we have more than enough teachers already, but I'm totally shocked to hear them say it," Coulson says. "It's kind of a third rail thing. You could never say that if you were a politician."
Part of the reason why politicians would shy away from voicing this sentiment is that Americans, by and large, love teachers, and want more—not fewer—of them in their local schools. Most Americans say they trust public school teachers and a majority say they're not in favor of reducing costs by hiring fewer teachers, according to a 2011 Gallup poll. American parents also favor small class sizes for their kids. (And, if they can afford it, are willing to pay a premium for smaller class size. Private school classes are smaller on average than public school classes.) Teachers unions also push for smaller class size.
Romney faced skepticism from teachers last week when he said that he doesn't think class size helps lift student performance. As governor of Massachusetts, he opposed measures to reduce class size.
[Related: Teachers respond to Romney on class size]
Over the past few decades, two dozen states have passed laws setting a cap on the number of students that can be in a class. There is evidence that smaller class sizes increase achievement, especially among younger students, but it's an expensive reform because teacher salaries are usually the largest item in school districts' budgets.

