Megan McCardle starts us off:
To state the obvious, unions negotiate ironclad contracts to cover dozens, hundreds, or thousands of workers. Once they take effect, those contracts are rarely renegotiated, and they apply to every single worker no matter what the situation. So unions are always going to be looking for the simplest, least subjective metrics by which to measure their members. Furthermore, they will be looking for metrics which are not under the control of the other side. The school board cannot change how many years you have in service, or whether or not you have a degree. But it can change the curriculum, or the tests.
I believe that to be true, but I also believe that the problem goes much deeper than that. Pay-for-performance or merit-based pay would force the unions and the school administration (and the teachers themselves) to acknowledge just how many teachers really don’t perform well at all–and should not even be teaching, if the schools were to use objective criteria.
I’ve worked in a variety of industries and for a number of companies across the country. Some were unionized and some were not. My experience with the unionized entities supports the idea that unionized employers are particularly attractive to sprinters. By that I mean that these entities (public or private) are known as places where once one gets in, one is good for life. Therefore, all one needs to do is sprint a bit–fill out the paperwork, take the tests, put on the best possible show, call in any family/friend favors and otherwise take whatever steps are necessary in the very short term to get contract. After that, very little effort is required to remain employed and one can get on with whatever things in life are truly important.
Those who excel (whether teachers or manufacturing line workers or whomever) are not as concerned about getting and keeping a certain job as are sprinters. These people know that they will be able to get ahead based on their inclination toward paying attention and working hard. As a result, unions are not essential for these employees–and are in many ways detrimental to the employees’ anticipated progress in the workforce.
The power of unions is in numbers: the number of union members, and (perhaps more importantly these days) the number of dollars which are provided in union dues.
Teacher’s unions do not like merit pay because it would remove the incentives which tend to increase the power of the unions. And that, as we all understand, is very bad thing for everybody.