Experienced teachers are, on average, more effective at raising student performance than those in their early years of teaching. This gives rise to the concern that too many teachers leave the profession after less than a full career and that too many leave troubled inner-city schools for suburban ones. Until now, the roots of these problems have…

It is by now a familiar story, often told as a lament: teachers in United States continue to be paid according to the single salary schedule. They accrue better pay on the basis of years of experience and college units earned. Units may or may not be related to teaching assignment. Some districts have modestly tweaked this arrangement by paying a…