Matt Yglesias is making some sense with regard to teachers and the endless public debate about their worth:
… I run into what I think is a huge consistency problem in the messaging coming out of teachers unions. Sometimes I hear from union-affiliated folks that it’s unfair to attribute differences in student learning to differences in teacher skill, because everyone knows that socioeconomic and home environment factors drive a lot of this. Other times I see the American Federation of Teachers building a messaging program around the idea that its members are Making A Difference Every Day. To me this leads to the obvious conclusion that while socioeconomic and home environment factors do drive a lot of student learning, teachers are also making a difference every day. And it makes a lot of sense to ask which teachers are making the most difference… the teachers who are in the bottom percent of difference-makers are doing us little good, and we should try to replace them with other people.
Of course to do that, you need to measure student learning and that means tests. But now comes out the worry that educators are now “incentivized to raise test scores at any cost” and will become soulless stat-juking monsters. If this is true, though, then what happens is teachers are given zero financial incentive to perform well on the job. What if the only financial incentives teachers get are to obtain meaningless degrees and stick around long enough for pensions to vest? It’s fun to speculate on the extent to which educators are or aren’t driven by objective financial incentives, but you need a consistent psychological theory of the case. The hypothesis that a teacher who responds to an incentive-free system is going to have a highly effective pedagogical method that he then abandons in favor of pure score-gaming once faced with an incentive to get students to do well on tests doesn’t make sense…My own take is that talk of incentives is massively overrated…it’s about attracting and retaining high performers to your organization.
…which is why testing and performance-based pay, as well as the ability to fire teachers, when they fail, matter greatly.