Contrary to common perception, the major automakers have produced large increases in fuel efficiency through better technology in recent decades. There’s just one catch: All those advances have barely increased the mileage per gallon that autos actually achieve on the road.
Sound perplexing? This situation is the result of a trend newly quantified by MIT economist Christopher Knittel: Because automobiles are bigger and more powerful than they were three decades ago, major innovations in fuel efficiency have only produced minor gains in gas mileage.
Specifically, between 1980 and 2006, the average gas mileage of vehicles sold in the United States increased by slightly more than 15 percent — a relatively modest improvement. But during that time, Knittel has found, the average curb weight of those vehicles increased 26 percent, while their horsepower rose 107 percent. All factors being equal, fuel economy actually increased by 60 percent between 1980 and 2006, as Knittel shows in a new research paper, “Automobiles on Steroids,” just published in the American Economic Review.The puzzle basically boils down to an earn-more, spend-more cycle, where we continually fritter away the gains that technology has given us. Simply put, the technology of 20 years ago simply could not have produced a heavy, powerful SUV with any sort of fuel efficiency whatsoever. Now that it's feasible, we want it, and consumers want the power and size more than we care about the added fuel economy. As a result, overall fuel economy stays pretty much constant, while the cars we drive change drastically.
This is a pretty difficult problem to solve, and not just in the arena of automobile manufacturing. When we as a nation earn more money or become generally more productive, we rarely redirect our newfound earnings (or time) into productive avenues--instead, we fritter it away on conspicuous consumption or myriad time-wasting activities. If we ask ourselves why, the answer is invariably hidden among many layers of complex and bizarre human psychology, often augmented or reinforced by a herd mentality. Yes, I'm rambling.
Ultimately, though, this is just another obstacle to technological progress, the first of which--our societal aversion to change--I mentioned in this post several months ago. Having good ideas available is a necessary condition, but not sufficient. To move forward as a society, we must be willing and able to truly embrace the new possibilities that have been opened up for us--and not to fritter those possibilities away mindlessly. In the case of fuel efficiency, it seems, we've been our own worst enemy. That's too bad.