Maybe, says a new study of the latest example of the law of unintended consequences.

ScienceDaily (May 21, 2008) — A ban on cigarette smoking in bars is meant to save lives by reducing patrons’ exposure to secondhand smoke. But it may actually be having an unintended consequence, according to a study done at the University of Wisconsin-Milwaukee (UWM).

By comparing data from a variety of locations around the United States where laws requiring smoke-free bars exist with locations without bans, economists Scott Adams and Chad Cotti found a relative increase in fatalities caused by drunk driving following ban enactment.

The results of their study appear in the June issue of the Journal of Public Economics and have also been reported in the May issue of The Economist.

While the results at first seemed surprising to Adams, a UWM assistant professor of economics, and Cotti, now at the University of South Carolina, literature on consumer behavior suggests an explanation: Smokers are willing to drive longer distances to an establishment that allows smoking.

“Like they would to buy fireworks, lotto tickets or, in some cases, alcohol, people will often go to a neighboring jurisdiction that doesn’t have a ban,” says Adams. The number of smokers willing to drive extra distances offsets any reduction in driving from smokers choosing to stay home following a ban, he adds.