Ruh-roh. An inconvenient truth: Fuel-efficient vehicles may not be saving the environment as much as you thought.
A new study in The RAND Journal of Economics finds that owners of eco-friendly cars tend to spring for a second vehicle that is much less eco-friendly, thereby tragically negating most environmental gains of the eco-friendly car. Most (75%) U.S. cars are purchased into multi-car households.
You see this phenomenon everywhere: The family that owns one eco-friendly commuter car, and one gas-guzzling minivan or SUV. “We think of every car as this separate purchase that doesn’t rely on any other things going on in the household, and that’s just not the case,” says lead author James Archsmith, assistant professor of agriculture and resource economics at the University of Maryland. “Other vehicles, priorities, and how those purchases and the intended uses of the vehicles interact are all important to understand how effective our policies are.”
He says that current policies encouraging the purchase of fuel-efficient cars are problematic because they do not take into account owners’ other vehicle purchases.
The researchers looked at six years of vehicle records from the DMV in California, the state with the country’s most progressive fuel economy standards, and thus a large number of fuel-efficient cars on the road. More bad news: The study also found that owners of fuel-efficient vehicles a tend to drive those cars longer and further, which further negates their emissions benefits. Le sigh.
Archsmith emphasizes that car buyers are not consciously deciding to splurge on hulking gas guzzlers; rather, they weigh practical comfort and utility, such as fitting the whole family in the car for a road trip. Other studies have found similar consumer behavior on purchases, such as the “diet soda effect,” where consumers who order a diet soda are more likely to add fries or a dessert onto the order.