Eduardo Porter attempted to take the air out of one of the few carbon mitigation programs the Obama Administration has been able to approve, the increase in fuel economy standards. Porter’s perspective is basically that increased gas taxes make more sense than higher fuel economy, and that the latter carries unintended consequences. For the first point, Porter cites this evidence.

Fuel-efficiency standards do not really change drivers’ behavior in a helpful way. Gas taxes do [...]

In 2008, when the price of gas shot abruptly past $4 a gallon, Americans cut back sharply on their driving. Total miles driven on American highways declined for the first time since 1980 and gas use fell more than 4 percent. General Motors ditched the Hummer, and gas-guzzling pickups were briefly dislodged from the perch they had occupied since 1992 as the nation’s most popular light vehicle.

Driving levels started creeping back up as soon as gas prices started receding, but a gas tax would be permanent and would lead to even bigger changes in habits. And the cost is lower than it seems. Economists point out that the energy savings would not change if the government returned all the revenue raised by a gas tax to Americans — perhaps through rebates for low-income people who spend a bigger share of their money on gas.

By contrast, Porter says that fuel economy rules do not affect driver behavior. They also take longer to filter into the overall picture of gas usage, because they don’t make an impact until the fleet gets turned over and people buy more fuel-efficient cars. A gas tax, in his eyes, has a more immediate impact. Moreover, more fuel-efficient cars carry an incentive to drive more, which he says leads “to more congestion, accidents, pollution and gas consumption.”

A few things. First, Porter in the previous story hails the fact that the 2008 gas price spike led to the purchase of more fuel-efficient vehicles. You cannot endorse that under one theory while decry it as too slow in another. What’s more, while I support a higher gas tax – the US has one of the lowest in the world – it must get combined with options for people who need to move around their area, in the form of mass transit and walkable residential living spaces. Otherwise, this just gouges consumers who have no other options.

I guess I agree with Felix Salmon on this. Ultimately, all of these parts must move together.

Porter is also right that in countries with higher gas taxes, fuel economy tends to be much higher. But he’s not necessarily right that the higher gas taxes alone are responsible. Porter implies that the US only has fuel-economy standards just because “a tax on gasoline doesn’t stand a chance” of being passed. But the fact is that even countries with very high gas taxes have fuel-economy standards as well. And, guess what, they’re significantly tougher than ours, and they always have been [...]

The fact is that fuel-economy standards are a pretty good way of ensuring that carmakers can plan for a more fuel-efficient future, without worrying about competitors undercutting them with gas-guzzlers. If the US government ever comes to its senses and increases the gas tax, or if it — wonder of wonders — actually implements a broader carbon tax, then at that point you would have three different forces conspiring to make America’s fleet more efficient. You’d have the tax, you’d have the fuel-economy standards, and you’d have the general global increase in fuel efficiency.

Without new taxes, we’re down to two; and without new fuel-efficiency standards either, we’d be down to just one. And that’s dangerous, because the US market is big enough that at that point there’s always a risk that we could replay the era of SUVs and Hummers, with manufacturers of small, efficient cars running a risk that they might get crushed if oil prices fall.

It’s a yes-and, rather than an either-or, in other words. I recognize the possible limits of fuel economy and how it may induce longer times on the road. But consider that vehicle miles traveled have been going down in the United States over the past few years, in a time where more economic vehicle options have rolled out. The best way to change the use of cars and fuel is to change the culture of endless driving, and that’s actually happening.