Illumination | Spring 2008

To illustrate this "selection effect," Podgursky draws a bell curve on the dry-erase board hanging in his office. "If all teachers were equally effective, then this might not have such a bang, but here's what we're observing," he says, pointing to the area of the curve representing the least effective teachers. "For every one of these who leaves, who gets replaced by an average teacher, you get a bump in performance."

Over time, he adds, this creates no small effect. Studies from the business world suggest about half of the gains from performance pay come from this selection effect. With some studies showing a positive motivation effect and others indicating a positive selection effect, Podgursky says, "there is a green light for districts to go out and begin experimenting here."

MOTIVATION EFFECT:Incentives tend to attract and retain people who are good at the activity for which there is an incentive, economists say.

Podgursky concedes that his research does not go so far as to reveal a best set of practices -- for example, an optimal size of bonuses or a mix of individual versus group incentives. Districts, he says, will have to use "trial and error" to determine the best system for them.

And that has some educators concerned.

"The devil is in the details," says Carolyn Herrington, dean of the MU College of Education. "I think among educators in general, we'd be concerned if policymakers go down this road too quickly."

Those who argue against pay-for-performance voice three main concerns: It encourages "teaching to the test," evaluations are too subjective and it promotes unhealthy teacher competition.

"Teaching to the test" refers to the phenomenon of teachers and/or schools narrowing their curriculum to focus only on those subjects being tested. "There's a lot of argument out there that that's occurring under No Child Left Behind, that because we just test math and communication arts, that schools are dropping arts and so on," Podgursky says. "I haven't seen any systematic data on it, but there are enough anecdotes out there and commentary to suggest that there probably is some of that."

A fear of a narrowed curriculum is one reason the National Education Association, the nation's largest teachers union, opposes any program that ties incentives to test scores. "Any system that has us teaching to the test and narrowing the curriculum is not a good system," says Bill Raabe, director of the National Education Association's collective bargaining and member advocacy unit.

Herrington agrees, adding that not only do the untested subjects have value in themselves, but they also have value in keeping kids eager to learn. Many kids look forward to school because of music, art and P.E., she argues.

Published by the Office of Research.