In July 2015 the Obama White House released a report on occupational licensing. “Today, one-quarter of U.S. workers must have a State license to do their jobs, a five-fold increase since the 1950s.”
The report also named costs. “Licensing requirements vary substantially by State, creating barriers to workers moving across State lines …” It cited research finding that “more restrictive licensing raises prices for goods and services provided by licensed professionals.”