Electric cars are worse for the environment per mile than comparable gasoline-powered cars, according to a new study published by the National Bureau of Economic Research. This contradicts the common assumption that electric cars are cleaner. In spite of this, the federal government still pays $7,500 for every electric car purchased — a subsidy the nation would be better off without, say the authors.
The study was authored by four economics and business professors: Stephen Holland (University of North Carolina, Greensboro), Erin Mansur (Dartmouth College), Nicholas Muller (Middlebury College) and Andrew Yates (University of North Carolina at Chapel Hill).
In monetary terms, electric cars are about half-a-cent worse per mile for the environment than gas-powered cars, on average. This means that if a government wants to tax a car based on how much it pollutes, electric cars should be taxed half of one cent more per mile driven than gasoline cars.
Much depends on where the car is driven. Gas-powered cars do worse in congested urban areas. For example, in Los Angeles, electric cars are 3.3 cents per mile better for the environment than gas-powered cars. Outside of metropolitan areas, electric cars are 1.5 cents per mile worse than gas-powered. In Grand Forks, N.D., for example, electric cars are 3 cents per mile worse.
Despite this variation, the federal government maintains a one-size-fits-all electric car subsidy. There may be ways to improve the current policy without eliminating it altogether, but the authors argue that elimination would be better than the current policy. "Because electric vehicles, on average, generate greater environmental externalities than gasoline vehicles, the current federal policy has greater deadweight loss than the no-subsidy policy," the authors write.
In theory, it would make more sense for state and local governments to offer their own subsidies, since the electric versus gas-powered calculus changes in different localities. But this, too, would create problems.
In 38 states, an electric car purchase reduces air pollution in that state. But residents in other states should be worried. "This purchase makes society as a whole worse off because electric vehicles tend to export air pollution to other states more than gasoline vehicles," the authors write. "Over ninety percent of local environmental externalities from driving an electric vehicle in one state are exported to others."
Rather than subsidizing vehicle purchases of supposedly-green cars, governments should tax cars per miles driven, say the authors, with tax levels varying depending on environmental consequences.
Although the typical assumption is that electric cars are cleaner than gasoline-fueled cars, the power for electric cars has to come from somewhere, and it's often from coal-fired power plants. "Rather than simply accepting the assertion of environmental benefits from electric vehicle use, this paper conducts a rigorous comparison of the environmental consequences of gasoline and electric powered vehicles, specifically by quantifying the externalities (both greenhouse gases and local air pollution) generated by driving these vehicles," the authors write.