What predicts a good employee? Well, number one is something that was outlawed by the Supreme Court. Number two is something that is hard to really look at, until the employee starts.
Anyways, 85 years of social science says years of education doesn't mean much, but IQ does. As one of the commenters in the blog says, that's largely because most people nowadays that are applying for the same job tend to have roughly the same education. So, duh having more education is not going to matter much. But, it is funny to think if you are interviewing for a position where your education level is "too much" it won't help you more then handwriting analysis.