I am wondering about the other market. This is the market for teaching evaluations. There are two types – some from students and some from class visitations. We all know about the market for high student evaluations. Teachers demand them and students supply them provided the professor plays his or her cards right. As far as I can tell there is no evidence that high evaluations are actually correlated with good teaching so, in this market, “playing them right” probably means something other than being effective and may require not being all that effective.
This leaves the written evaluations provided by class visitors. I am not sure it is fair to call this a market. I mean, is it a market when the suppliers are giving the laudatory letters away? In twenty years law teaching I could count on one hand the number of even remotely negative letters I have seen. It could be that the teaching is excellent on visitation days. (I have heard of an incident in which the faculty visitors discovered that the teacher was teaching the same material whenever they visited. You can bet that he had that day’s material down.) Or maybe it is really easy to be a good teacher – at least three or four days a year when you know someone is coming. If the tenure or promotion candidate is a social or political favorite, you can bet that those written evals are out of sight regardless of what went on in the classroom.
What does it matter? There are a couple of costs. First, creating a file full of overblown letters may come back to bite you in the butt if there is a change of heart. Second, since no one believes that every tenure and promotion candidate is as great as the letters say, Law Schools and law professors lose credibility with every subseqent reviewing body -- even those that appear to play along.
But maybe this is not a cost to the professors themselves. Afterall, they are always playing with house money.