[faeriechangling]

All taxes are behaviour disincentives. If we tax say income but not pollution, we're discouraging people from working while the price of pollution is not paid by the polluter. If we're subsidising clean cars at the same time, w'ere also having wage earners subsidise cars for the upper-middle class.

This is great if you enjoy polluting and not working, such as if you're a trust fund kid who likes to drive his big car everywhere while the poor and workers suffer the consequences, but is not a societally conducive state of affairs.

With cars, every incentive you can devise has reverse Robin Hood effects since the poor use transit and bicycles, and both incentives and disincentives are being used in practice anyways. It's in fact perfectly fair for people inflicting an unpriced externality on the broader population, through pollution, to pay a fraction of the cost of that externality themselves. If that disincentivizes the behaviour - is that so morally outrageous?

Is it truly fairer to instead bribe this wealthier than average group of polluters into not polluting through taxes on the rest of the population? If anything this creates a moral hazard insofar that it would seem the key to getting the government to subsidise your expenses is simply to pollute relentlessly and inflict costs on the rest of society and say "You can't just TAX us, you need to tax everybody else and pay us off!"