Randal O’Toole explains in a Cato Institute commentary why lower oil prices represent good news, not the bad news lamented by some pundits.

Low oil prices generate huge economic benefits. Low prices mean increased mobility, which means increased economic productivity. The end result, says Bank of America analyst Francisco Blanch, is “one of the largest transfers of wealth in human history” as $3 trillion remain in consumers’ pockets rather than going to the oil companies. I wouldn’t call this a “wealth transfer” so much as a reduction in income inequality, but either way, it is a good thing.

Naturally, some people hate the idea of increased mobility from lower fuel prices. “Cheap gas raises fears of urban sprawl,” warns NPR. Since “urban sprawl” is a made-up problem, I’d have to rewrite this as, “Cheap gas raises hopes of urban sprawl.” The only real “fear” is on the part of city officials who want everyone to pay taxes to them so they can build stadiums, light-rail lines, and other useless urban monuments.

A more cogent argument is made by UC Berkeley sustainability professor Maximilian Auffhammer, who argues that “gas is too cheap” because current prices fail to cover all of the external costs of driving. He cites what he calls a “classic paper” that calculates the external costs of driving to be $2.28 per gallon. If that were true, then one approach would be to tax gasoline $2.28 a gallon and use the revenues to pay those external costs.

The only problem is that most of the so-called external costs aren’t external at all but are paid by highway users. The largest share of calculated costs, estimated at $1.05 a gallon, is the cost of congestion. This is really a cost of bad planning, not gasoline. Either way, the cost is almost entirely paid by people in traffic consuming that gasoline. …

… In short, rather than $2.38 per gallon, the external cost of driving is closer to around 26 cents per gallon. Twenty cents of this cost is steadily declining as cars get cleaner and all of it is declining when measured per mile as cars get more fuel-efficient.

It’s worth noting that, though we are seeing an increase in driving due to low fuel prices, the amount of driving we do isn’t all that sensitive to fuel prices. Real gasoline prices doubled between 2000 and 2009, yet per capita driving continued to grow until the recession began. Prices have fallen by 50 percent in the last six months or so, yet the 3 or 4 percent increase in driving may be as much due to increased employment as to more affordable fuel.

This means that, though there may be some externalities from driving, raising gas taxes and creating government slush funds with the revenues is not the best way of dealing with those externalities.