The history of licensing of doctors and dentists is covered in the book &quot;Competition And Monopoly In Medical Care&quot; by Frech. Much of the motivation for licensing was reducing the number of doctors so they could raise prices. Licensing also enabled pervasive discrimination against Jewish, black, and female doctors (pg. 54).<p>&quot;one benefit of licensure requires that it confer monopoly rents upon physicians.&quot; pg. 58<p>There&#x27;s a lot more in the book.