So here's a link to the Register's editorial deploring the fact that California requires licenses (permission from the nanny state) to do more jobs than any other state in the nation. Vocational licensing is sold as a consumer protection device, but it's blatantly nothing of the sort. It's a scheme to limit competition and increase the income of practitioners while discouraging innovation.
I was convinced years ago by Milton Friedman's "Capitalism and Freedom" that we'd be just fine without state licenses for doctors or lawyers (which wouldn't rule out certification, perhaps from competing organizations, which would undoubtedly be more rigorous than the state system). In fact if you study the history of medical licensing, which was completed around 1910 with the Flexner Report, it becomes pretty obvious that it was a pretty sleazy operation that had a lot more to do with increasing incomes than protecting patients.