Non-competition agreements - an academic study

I mentioned the usefulness of the Harvard Business School's Working Knowledge newsletter in this post. Here is an example of its usefulness: an interview of a researcher into how non-compete agreements affect employee mobility. The following comes in the preface to the interview:

What they found: While noncompetes do constrain mobility in a demonstrable way, more important was that these effects were amplified for inventors with particular characteristics. As Marx explains, the results suggest that "star" or "specialist" inventors wishing to explore career opportunities may need to look outside a state that enforces noncompetes.

The article provides a link to the study (33 pages in PDF format). I am working on reading the study. I am not sure if will or will not have any practical use in litigating covenants not to compete, but I can say that it has some interesting policy implications.