Occupational licensing is the process of obtaining permission from a government to practice a profession or trade. According to S. David Young, "today at least a fifth, and perhaps as much as a third, of the work force is directly affected by licensing laws" in the United States. 
 Effects of occupational licensing
According to Morris Kleiner: "Occupational licensing has either no impact or even a negative impact on the quality of services provided to customers by members of the regulated occupation. Additionally, as occupations become licensed, members of regulated occupations see their earnings go up."
Occupational licensing was a problem in 1776 when Adam Smith wrote in The Wealth of Nations: "The property which every man has in his own labour, as it is the original foundation of all other property, so it is the most sacred and inviolable. The patrimony of a poor man lies in the strength and dexterity of his hands; and to hinder him from employing this strength and dexterity of his hands; and to hinder him from employing this strength and dexterity in what manner he thinks proper without injury to his neighbour is a plain violation of this most sacred property."
Mises Institute scholar Michael Rozeff states: "In the shorter term, the interest groups use the state against the public. In the longer term, the state and its bureaucrats rule the roost. In the end, the government bureaucracies expand."
According to Morris M. Kleiner and Alan B. Krueger: "During the early 1950s, less than 5 percent of the U.S. work force was covered by licensing laws at the state level. That grew to almost 18 percent by the 1980sβwith an even larger number if federal, city and county occupational licensing is included. By 2000, the percent of the workforce in occupations licensed by states was at least 20 percent.
- S. David Young. "Occupational Licensing", Library of Economics and Liberty. Referenced 2010-11-29.
- Lee McGrath. "A Primer on Occupational Licensing With Professor Morris Kleiner", Institute for Justice, April 2008. Referenced 2010-11-29.
- Adam Smith. "The Wealth of Nations", Book I, Chapter 10. Referenced 2010-11-29.
- Michael Rozeff. "Who Captures Whom? The Case of Regulation", Mises Daily, September 28, 2006. Referenced 2010-11-29.
- Morris M. Kleiner, Alan B. Krueger. "The Prevalence and Effects of Occupational Licensing" (pdf), August 2008. Referenced 2010-11-29.