I think throwaw181ay is making a different argument, which is essentially that you should license the people (e.g. like a driver's license, which indicates proficiency) and not the thing, which is (basically) the car.

And they do -- you acquire the taxi driver certification ("this guy has good eyesight, isn't a criminal, knows the taxi rules") independently of the medallion ("no more than N cabs may be operating at any given time"). The two regs accomplish different purposes.

As the parent notes, in certain setups (like cap and trade) the tradeability of the license is important for ensuring that the restricted resource is used efficiently: the most economical emitters of carbon get the rights, and the most economical drivers get the medallions.

> the medallion ("no more than N cabs may be operating at any given time")

The whole point of this is to ensure that the price for taxi rides is higher than what the market-clearing price would be. In other words, it's a scam to rip off gthe consumer.

(Similar arguments apply to zoning regulations and house prices, of course)

There are good motives and bad motives behind every law. I don't find it productive to assert, as fact, that the malicious stuff is only kind, without addressing the good that they're ostensibly accomplishing.

You might as well dismiss all cap-and-trade proposals as being "just another scheme to raise energy prices".

As far as I knew, taxi licenses were there specifically to certify that the driver was trustworthy. After all, the service involves getting into a stranger's car...

A cap-and-trade scheme is a reasonable option if your goal is to limit the quantity of something (like carbon emissions) while allowing the market to behave as normal otherwise.

But there's no direct reason to limit the number of taxis. People suggest that limiting the supply ensures drivers make a decent living, but if you want that, employment law (e.g. enforcing minimum wage for drivers) is a more direct solution.

Considering the negative externalities of taxis on their environment (noise, pollution, congestion, and of course occasionally killing people) there are quite likely reasons to limit the number of taxis.

>(noise, pollution, congestion, and of course occasionally killing people)

Again, if we want to limit these things, we should make laws about them directly, rather than arbitrarily limiting one of their causes. Solutions to negative externalities should be primarily based on internalising those externalities, so the market has an incentive to seek alternatives.

What happens if someone invents a more expensive, but quiet and non-polluting taxi? (Which of course, they have.) If you limit the number of taxis, everyone uses the cheaper ones to maximise profit, and you still get some noise and pollution. Whereas if you tax the noise and pollution and it becomes cheaper to buy electric taxis, you've eliminated the noise and pollution entirely.