There are some really egregious examples of state licensing — the Institute for Justice has done great work suing to get this stuff under control. Speaking of hairbraders, one of IJ’s better known cases involved a suit against the District of Columbia for requiring 1,500 hours of training to braid hair. I’m pretty sure you could get a commercial pilot’s license in less time.

Another reader who happens to be a plumber makes another good point here:

“Joe the Plumber” said he was thinking of buying a (plumbing) business not proforming the job of plumber. You don’t need a licence yet to own a business, plumbing or otherwise.
In my local it is more difficult to get a plumbing licence than to be a doctor — well, it takes longer.

And finally, another correspondent writes into say Fox news reported tonight that Joe is preparing to take his test for a commercial plumber’s license. So there you go.