The same testing they do now. It just wouldn’t be mandatory to be in business.
Do you really have to go through Cosmetology school to cut hair? No. But it’s required to open or work in a shop in all states as far as I know.
The issue is, what’s your competence to do the job? If someone is willing to go with your own stated competence, they just assumed all the risk. If the State is saying you passed a test, then in some form they are taking away that risk. Possibly Tort law can reflect that. But you would still be free to choose.
Why should the state have such a bureaucracy anyway? Let them get tested by their cosmetology school and graduate or not, we don’t need taxpayers funding bureaucrats running around testing people on stuff like this.
The new Governor of Texas has the right idea:
http://www.gregabbott.com/making-easier-business/
excerpt:
There are currently 150 business activities that currently require a state-issued license before they can be legally performed in Texas. Some of these are necessary for the health and safety of our citizens, like licensing medical doctors.
But many are unnecessary or overly burdensome. For example, why do we require a license to be an interior designer? Or a salvage vehicle dealer? Or a “shampoo apprentice”?