While writing a column on public sector compensation, Jacob Vigdor’s research on teachers came to mind:

Teachers with more experience are automatically paid more in North Carolina, and in virtually every other public school system in the country. Research has shown that experienced teachers are more effective in the classroom. So the real-world salary schedule looks a lot like the “evidence-based” schedule, right? Not exactly. …

Relative to a teacher just beginning in the profession, teachers with one or two years of experience raise test scores by an extra 5 percent of a standard deviation. They are paid, on average, 2 percent more than starting teachers. If the standard were to pay teachers an extra 1 percent of salary when they raise test scores by 2.5 percent of a standard deviation, then highly experienced teachers who post a 25 percent test-score advantage over rookies should be paid a 10 percent premium. Instead, their premium approaches 70 percent. Visually, the darker bars rise quickly at first, moving from left to right, but largely level off once a teacher has six years of experience. The salary schedule marches right along, providing continuously increasing rewards to teachers as they progress from 6 to 27 years of experience, even though their classroom effectiveness has barely improved.

The existing salary schedule rewards teachers too little for the substantial improvements they post in the first few years on the job, and too much for the later years of their career, when they show only incremental advances. An evidence-based salary schedule would alter this arrangement, focusing the rewards on the early rungs of the experience ladder.

Basically, we need to pay teachers more earlier in their careers and somewhat less later in their careers if we want to maximize bang-for-buck. This would tend to save money, which Vigdor suggests we then plow back into increasing starting salaries. Coupled with pension reforms, we’d make the returns to teaching more front-loaded.

This would tend to raise the quality of the teacher talent pool over time. Vigdor proposes a number of other reforms, including rewarding teachers for evidence of greater effectiveness rather than for completing advanced degree programs. This would incline teachers to only enroll in advanced degree programs with a proven track record of improving effectiveness. 

I’d love to see Vigdor’s approach embraced by more school districts. There are, naturally, formidable political barriers:

Given the losses to experienced teachers, and the likely opposition of those in the business of educating teachers, is the evidence-based salary schedule a pie-in-the-sky ideal with no chance of becoming reality? Not necessarily. Entry-level teachers will find it in their best interest to choose the new system, if given a choice. The relative benefits become even more obvious if they intend to stay in the profession only a few years.

Phasing in the system, applying the evidence-based schedule to new teachers while retaining the traditional schedule for those who wish to remain on it, would shift the burden from highly experienced teachers. Of course, this burden would not disappear. It would shift to taxpayers, who would have to finance higher levels of teacher salaries until the completion of the phase-in period, perhaps 20 years or longer. The costs of paying new teachers on the evidence-based schedule while keeping existing teachers on the traditional schedule would peak after 10 years, at which point savings associated with the flattened rewards for experience would begin to outweigh the costs of higher salaries to younger teachers.

I strongly recommend following Vigdor’s work on teacher incentives, particularly his extensive empirical work on North Carolina’s experience.