Massachusetts's enforcement of non-competes and poor performance relative to California is the classic variation, first (or at least famously) pointed out in 19

Massachusetts's enforcement of non-competes and poor performance relative to California is the classic variation, first (or at least famously) pointed out in 1994 and subject of many studies since; http://webdoc.sub.gwdg.de/ebook/serien/lm/DRUIDwp/10-02.pdf http://webdoc.sub.gwdg.de/ebook/serien/lm/DRUIDwp/10-02.pdf is one from 2011 that extends analysis to all US metros: less enforcement correlated with more employment, business establishments, and patents (sigh) even if the SF bay area is excluded.