In the 1980s, school districts dabbled with programs that offered teachers cash inducements, such as bonuses or raises, for doing their jobs well. But those merit-pay programs were mostly short-lived, hotly debated, and understudied. Even after all this time, no one knows definitively whether children learn more when teachers are paid extra for boosting their students' achievement. Now "pay for performance" is in vogue again, with programs operating in Florida, Minnesota, Texas, and Denver, among other places. This time, though, a group of researchers at Vanderbilt University is seizing the chance to put those initiatives under the microscope. With a five-year, $10 million grant from the U.S. Department of Education's Institute of Education Sciences, the newly established National Center on Performance Incentives has put together an ambitious agenda to study such efforts in Nashville, Tennessee, across the state of Texas, and in two other locations yet to be named. In the end, the center's researchers hope to shed light on whether teachers behave differently when the prospect of bonuses is dangled before them, whether student achievement improves as a result, and whether the existence of such programs will ultimately attract a different mix of teachers into the field.