Mark’s justification for prohibiting unlicensed persons from doing plumbing needs a little more unpacking, though it wasn’t the point of his post. First, some nice words about plumbers: I don’t have the citation, but I read somewhere that if you separate the drinking water from the sewage, which is precisely what plumbers do and what most of the plumbing code provisions are designed to assure, you double life expectancy from 35 to about 70; adding all of medicine’s wonders gets you maybe another five. (Pipefitters do stuff like gas, steam, and chemical, um, pipefitting, which is all good but off the topic here.)

Framing licensing laws as prohibitions is important: nothing obliges Joe to have a plumbing license or any other kind of a license. Actually, in most jurisdictions, you don’t even need such a license to do plumbing as long as it’s in your own house. That prohibition is against occupying the house unless you got a permit to do the work, with an inspection by the city, an inspection that applies also to all work by licensed plumbers and in principle makes the license redundant.

So subsequent buyers of houses owned by reasonably handy people are not protected by licensing requirements but by a different complex of convention and law, including not just inspections and permits but also the difficulty (owing to thread and pipe sizes, for example) of putting plumbing parts together wrong, the evidence of defect typically corrected with a mop and noted with profanity, and the wide availability of pretty good “how-to” books and TV programs. Clerks at hardware stores used to be part of this web of quality assurance but times change and Lowe’s/Home Depot floor staff apparently have some completely different function. The brevity of their moments of visibility in this universe so far has made it impossible to discern what this is.

I’m not entirely a libertarian about this, definitely not ready to sweep away all professional licensing: inspectors can’t always see everything. But we certainly do too much of it. Let’s remember that forbidding unlicensed plumbers to do plumbing as paid work for others is motivated at least in part by its very salutary effect on everyone inside the tent (licensed), keeping prices high by suppressing competition. Getting the state to force your competitors out of business is like actually out-competing them to gain market share, but cheaper, and you get to do it in nice clothes, in fancy restaurants in the state capital, instead of under someone’s house in Carhartts on Sunday. The ghost of the late great Mancur Olson here reminds us that the members of such groups are few, have high stakes in policy, and know who they are, while the rest of us are diffuse, many, and have low per capita stakes. Guess who wins? Many trades, like the fellowship of suers, pleaders and briefwrights, have even arranged for the members of their group to be the sole judges of who can join their legally protected monopoly and on what terms, which is not just rent-seeking but bumper-harvest rent-gathering.

Tilting the pinball machine of business one’s own way is why hairdressers and manicurists often exhibit such a powerful drive to protect the public in this way, and why people who have not yet succeeded in getting these protections enacted for themselves often gin up alternate paths to the same end, like requiring certain jobs in government to be held by people with this or that degree (planners and teachers, for example) or using union membership similarly.

I must at this point clarify the precise scope of the foregoing argument lest our readers be misled. For extremely arcane but absolutely incontrovertible reasons (much too technical to actually explain here, please keep reading right along, thank you) three and only three professional identities completely satisfy the most rigorous theoretical and empirical standards for very strict licensing, namely architects, engineers, and university professors. Maybe college professors, if they behave in a deferential fashion and pay some extra dues. To even consider that just anyone be permitted to wield the sacred instruments and mysteries of these three callings is to invite Really Bad Stuff Happening, I shudder at the thought, wow, what a nightmare. Everyone else, line up to have your market entry restrictions reviewed from scratch, please.

Author: Michael O'Hare

Professor of Public Policy at the Goldman School of Public Policy, University of California, Berkeley, Michael O'Hare was raised in New York City and trained at Harvard as an architect and structural engineer. Diverted from an honest career designing buildings by the offer of a job in which he could think about anything he wanted to and spend his time with very smart and curious young people, he fell among economists and such like, and continues to benefit from their generosity with on-the-job social science training. He has followed the process and principles of design into "nonphysical environments" such as production processes in organizations, regulation, and information management and published a variety of research in environmental policy, government policy towards the arts, and management, with special interests in energy, facility siting, information and perceptions in public choice and work environments, and policy design. His current research is focused on transportation biofuels and their effects on global land use, food security, and international trade; regulatory policy in the face of scientific uncertainty; and, after a three-decade hiatus, on NIMBY conflicts afflicting high speed rail right-of-way and nuclear waste disposal sites. He is also a regular writer on pedagogy, especially teaching in professional education, and co-edited the "Curriculum and Case Notes" section of the Journal of Policy Analysis and Management. Between faculty appointments at the MIT Department of Urban Studies and Planning and the John F. Kennedy School of Government at Harvard, he was director of policy analysis at the Massachusetts Executive Office of Environmental Affairs. He has had visiting appointments at Università Bocconi in Milan and the National University of Singapore and teaches regularly in the Goldman School's executive (mid-career) programs. At GSPP, O'Hare has taught a studio course in Program and Policy Design, Arts and Cultural Policy, Public Management, the pedagogy course for graduate student instructors, Quantitative Methods, Environmental Policy, and the introduction to public policy for its undergraduate minor, which he supervises. Generally, he considers himself the school's resident expert in any subject in which there is no such thing as real expertise (a recent project concerned the governance and design of California county fairs), but is secure in the distinction of being the only faculty member with a metal lathe in his basement and a 4×5 Ebony view camera. At the moment, he would rather be making something with his hands than writing this blurb.