A particularly useful categorization of occupational regulation was developed by Wolfson et al. (1980). It distinguishes between regulation of outputs (forcing producers out of an occupation v. letting them stay in) and regulation of inputs (keeping producers out v. letting them in).
Output Regulation: Standard Setting and Enforcement
Output regulation focuses on performance, regardless of how accomplished. An authority whether government or a private agent-monitors the practitioners' job performance. Entry to practice would not be restricted, but exit could be forced for lack of compliance to standards (Wolfson et al. 1980).
Input Regulation: Certification
Certification (or reserved title) requires the additional input of training or education in the production process. Certified practitioners must receive training or education as determined by the certifying agent, which may be governmental or private. The value of certification, thus, depends upon the perceived prestige of the certifier by the consumers. Non-certified producers exist with certified producers and they compete with each other for business.
Input Regulation: Licensure
Licensure (exclusive right to practice) restricts production inputs such that only licensed providers can offer their services. Licensure can be provided by the government or delegated by it to another agent, either of which set the educational and experience requirements for practice. In either case, practicing without a license is proscribed by law.