The Rule of Cui Bono

The rule of cui bono: proponents of any political or economic program will always claim that their program benefits the public. Therefore the claim carries no information. The claim may be true, but it may be safely ignored. The real objective is to determine who else benefits, and who bears the costs.

What is cui bono?
From Wikipedia:

"Cui bono?" (/kwiː ˈboʊnoʊ/), literally "for whose benefit?", is a Latin phrase which is still in use^[1] as a key forensic question in legal and police investigation: finding out who has a motive for a crime. It is an adage that is used either to suggest a hidden motive or to indicate that the party responsible for something may not be who it appears at first to be.^[2]

The cases about which I'll ask "cui bono" will be political and economic--so we'll be using cui bono as a key forensic question to investigate other kinds of crime.

The standard answer is non-information-bearing
When you ask cui bono about a political or economic program, the one answer you'll always get is: "it will benefit the public." That's because the alternative response "this benefits some small set of people, but does not benefit the public" is a non-starter for a political or economic program. It may benefit the public, but it probably disproportionately benefits others.

A simple example
Let's try it out. Who benefits from professional licensing for barbers and cosmetologists? Maine regulates them, and here's what the state's website says:

The State Barbering and Cosmetology Licensing was established to protect the public through the regulation of the practice of barbering and cosmetology in the State of Maine. 

Of course, it's to protect the public. Rule number one if asking "Cui bono" is to ignore the claim that a particular rule will benefit the public because regardless of the real motivation, anyone with an ounce of sense will make that claim. Think about it. If someone wanted a law passed that would benefit them and only them, do think they would say "I want it passed for my benefit," or would they claim "I want it passed to benefit the public" and then figure out why something that was designed only to benefit them would actually benefit a lot more people--and ideally everyone?

This is not to say that a given rule might not benefit the public. Rather it's to say: ignore that argument because it bears no information. Everyone is going to say that. If no one, other than the broad public benefits, and there any costs (there will always be costs) are less than the benefits, then we can rest with that as the explanation.

However, this is never the case. There will always be other beneficiaries. In the case of Maine's licensing:

...The Program creates safety and sanitation rules and enforces these rules through regular inspections of licensed establishments and consumer complaints. In addition, the Program licenses and regulates schools that offer and provide professional practice courses in the field of aesthetics, barbering, limited barbering, cosmetology and nail technology.

There is a case to be made for safety and sanitation rules. Barbers use razors that may carry infectious agents from person to person. Beauticians may deal with chemicals that need more than ordinary care and knowledge. So the public certainly gets some benefit--though at a cost.

But does the rule benefit others? Of course. It benefits the person who is in charge of administering the licensing program. Even if that person carries out their job with complete integrity, their entire current livelihood depends on the existence of the regulation. That's a benefit. Not that such a person can't get another job. Any competent licenser of barbers and beauticians is probably able to get another job. But in the moment, that's their job, and there's a benefit to their continuing to have it and cost to taking it away.

And the rule benefits barbers who already have licenses and disadvantages aspiring barbers who don't yet have licenses. It will cost them time and money to get a license.

But it must be worthwhile. Having a license means that a barber no longer competes with all the people in their local job market and only with "people who already have licenses." Having a license must more than repay the cost of obtaining a license, or people would not get licenses. So licensed barbers benefit.

Bottom line: ignore any claim any program benefits the public. Look elsewhere for beneficiaries.