According to the Post-Dispatch, experience is not the sole factor to consider when hiring teachers:

That’s the conclusion of a new study released Wednesday that looks at the quality of public school teachers in Illinois.

The 44-page report from the Illinois Education Research Council found the highest percentage of academically talented teachers were at schools in the Champaign area, with those in suburban Chicago and west-central Illinois close behind.

I know this isn’t really shocking news for anyone who has given the subject serious thought. It seems fairly obvious that experience is only one of many factors that need to be taken into account when hiring mechanics, doctors, financial analysts, stock brokers, farmhands, dishwashers, sales clerks, and, yes, even teachers. So, surprise! This study confirms the obvious.

The reason this study is necessary at all is that unions have strong incentives to favor policies that benefit current workers at the expense of future workers. The result is an overemphasis on experience relative to other merits in the workplace. So it really shouldn’t be surprising when teacher unions favor experience-based pay and oppose merit-based pay — even when both common sense and science contradict them.