As the Trump administration considers a rollback of strict Obama-era fuel standards, which aimed to reduce greenhouse gas emissions from the transportation sector, a recent study has provided a new argument in their favor: They might actually save lives.
One common way automakers improve the fuel efficiency of their vehicles — that is, how much gasoline they consume per mile — is to reduce the weight of the automobile. And the new study, a working paper published by the National Bureau of Economic Research in April, suggests that a reduction in the overall average weight of vehicles on the road may actually result in fewer fatalities as a result of car crashes.
This means that, even for critics who are not interested in reducing greenhouse gases from cars, there’s still an argument to be made for keeping vehicle fuel standards, said Antonio Bento, an environmental economics expert at the University of Southern California and one of the study’s co-authors.
“What the paper shows is that even if those environmental benefits are very, very low, if nothing else, from a safety reason, you have a reason to move forward with the standards,” he said.
The federal Corporate Average Fuel Economy, or “CAFE” standards, were first introduced in the United States in 1975. In 2012, the Obama administration approved a more stringent set of standards, which would steadily increase the efficiency of certain vehicles through 2025. The standards also changed some of the ways efficiency requirements are applied to cars of different sizes.
Facing opposition from the automobile manufacturing industry, the administration later conducted a review of the standards but concluded at the end of 2016 that they would remain in place. However, the Trump administration decided in March to reopen this review — meaning it could decide to weaken or remove the Obama administration’s update.
Pushback against the CAFE standards is hardly new. Over the decades, industry members and other critics have levied a variety of arguments against them, and one of the most common from the beginning has been the idea that fuel standards sacrifice safety. Many critics have suggested that lighter-weight cars — which are typically more fuel efficient — are more likely to produce fatalities in an crash.
This may indeed be the case if you’re looking at a weight change in only one car. Say you observe a crash between two SUVs, both around the same size. If you downsize one of those vehicles to a Smart car, the chance of its passengers being injured or killed may increase. On the other hand, if you downsize both vehicles, the overall risk of fatality might actually become smaller than it was to begin with.
The researchers argue that, in the past, critics have only examined the effects of reducing an individual vehicle’s weight and not the standards’ overall effects on all vehicles in circulation — an important distinction.
“What CAFE actually does is it doesn’t just lower the weight of one vehicle,” said Kevin Roth, an environmental economist at the University of California at Irvine and another co-author of the study. “It changes the entire composition of the fleet.”
The researchers (who included Bento, Roth and co-author Kenneth Gillingham of Yale University) focused their study on two effects of the original CAFE standards: a reduction in the average weight of all vehicles on the road and a change in the dispersion of their weight — that is, how much variation there is in the weight of individual cars.