QUIETLY BUT wisely, the Commerce Department has decided to allow the first exports of U.S. crude oil since Congress imposed a ban on such sales (except to Canada) in the 1970s. To be sure, the agency’s ruling amounts to redefining crude in a way that applies only to a form of ultralight oil that U.S. refineries are ill-equipped to process. The executive branch couldn’t do much more than that to expand crude exports without congressional permission. Still, Commerce’s move is a step in the right direction because resuming oil sales abroad could help the U.S. economy reap the full fruits of the shale revolution that has propelled this country back into the top ranks of global oil and gas production.

The origins of the ban lie in the long-gone political and economic issues of the Nixon era. Specifically, the United States banned oil exports in response to the declining domestic production and Middle East supply shocks of that time, which, together with the then-existing system of U.S. price controls, made it seem rational to keep U.S.-produced oil at home rather than let it flow to the highest bidder on the world market. The world has changed dramatically since then; with U.S. production booming, this country is in a position to move the world market. Yet some still defend the export ban on the grounds that it holds down the price of crude to U.S. refineries and, by extension, the price of gasoline at U.S. pumps.

A new report by IHS Global explains why that thinking is outmoded. Actually, the report notes, allowing U.S. producers to sell their light crude abroad, where more refineries are equipped to process it efficiently, would incentivize additional U.S. production and job creation. At the same time, increasing the world supply of crude oil would translate into lower world prices for other heavier grades of crude, which U.S. refineries do use, and for gasoline. That, in turn, would be reflected in moderate gas prices in the United States. The IHS study estimates free trade in U.S. crude oil could save U.S. motorists $265 billion between 2016 and 2030. This does not count the geopolitical benefits of bringing a stable new source of supply onto world markets to offset those from Iraq, Libya and other trouble spots.

Fossil fuel consumption contributes to carbon emissions and climate change, so free trade in oil should be complemented by other policies to encourage lower consumption, such as a carbon tax. Even with the best such policies in place, though, a carbon-free energy future is years away — and in the interim U.S. consumers and industry will rely on oil and gas. U.S. policy should be to ensure that the world market for those commodities functions as flexibly and transparently as possible.