On the front page of today's WSJ, an excellent article about the rising occupational licensure in some states for some professions (see chart above, click to enlarge): "A License to Shampoo: Jobs Needing State Approval Rise," here are some key paragraphs:
"Mr. Kleiner, labor professor at the University of Minnesota, looked at census data covering several occupations that are regulated in some states but not others, including librarians, nutritionists and respiratory therapists. He found that employment growth in those professions was about 20% greater, on average, in the unregulated states between 1990 and 2000.
Licensing can also drive up costs to consumers. Licensed workers earn, on average, 15% more than their unlicensed counterparts in other states—a premium that may be reflected in their prices, according to a study published by the National Bureau of Economic Research and conducted by Mr. Kleiner and Alan Krueger, an economist at Princeton University.
Mr. Kleiner estimates that across the U.S. economy, occupational licensing adds at least $116 billion a year to the cost of services, which amounts to about 0.1% of total consumer spending. In a look at dentistry, Mr. Kleiner found that the average price of dental services rose 11% when a state made it more difficult to get a dental license.
In many service trades, licensure "is totally out of control," says Charles Wheelan, a lecturer in public policy at the University of Chicago. He says the marketplace might be a better judge than the government of whether a barber or a yoga instructor is competent. "It's fairly easy for you to tell whether you've gotten a bad haircut or not, and if quality turns out to be bad, it's not a big social problem," says Mr. Wheelan.
When a trade group does succeed in getting a licensing law passed, it sometimes exempts existing workers from the testing requirements. In Michigan, for instance, it will soon be a felony to practice massage without a license.
Newcomers to the field must take 500 hours of classes and pass an exam to get that license. But a grandfather clause exempts most current massage therapists, including those who may never have taken a class at an accredited school."
See Chapter IX ("Occupational Licensure
") of Milton Friedman's book "Capitalism and Freedom."