The 2015 Current Population Survey in the USA added a question about whether you needed a licence or a certificate to practice your occupation. One in 4 Americans say they need a licence or certificate. 22.4% need a license and 3.1% need a certificate among employed over the age of 16 in the USA.
Source: Bureau of Labour Statistics, Labor Force Statistics from the Current Population Survey (2015), Certification and licensing status of the employed by occupation Table 5.
This estimate of 25% is less than the 30% estimated by Kleiner and Vorotnikov (2015) using a Harris Poll. Kleiner and Vorotnikov (2015) also found that some American states regulate twice as many occupations as others. This diversity in federalism strains any public interest explanation of occupational regulation.
Occupational regulation is more likely to be an issue for those who finished further education. It would have been better if the estimate by the Bureau of Labour Statistics was for adults and not have included teenagers.
The purpose of occupational regulation is to protect buyers from quacks and lemons – to overcome asymmetric information about the quality of the provider of the service.
The main issue with quacks in the labour market is whether there is a large cost of less than average quality service, and is there a sub-market who will buy less than average quality products in the presence of competing sellers competing on the basis of quality assurance. This demand for assurance creates opportunities for entrepreneurs to profit by providing assurance of quality.
Mostly disciplinary investigations and deregistrations under the auspices of occupational regulation are for gross misconduct and criminal convictions rather than the shading of quality.