> A license shouldn't be sold.
Many proponents of cap-and-trade schemes disagree.
Many proponents of cap-and-trade schemes disagree.
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 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)
You might as well dismiss all cap-and-trade proposals as being "just another scheme to raise energy prices".
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.
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.