Boston ? The sickly economy may have a silver lining: Research shows tough times are good for your health.

In a paper published by the National Bureau of Economic Research in Cambridge, Mass., economist Christopher J. Ruhm concludes that when jobs are scarce, both unemployed workers and those who keep their jobs (but perhaps with less work to do) behave in a healthier manner.

They’re more likely to exercise, less likely to pig out at restaurants or skip doctors’ appointments, he concluded. Also, it’s the heaviest smokers and most obese who change their behavior during a slump.

Ruhm’s idea flies in the face of conventional wisdom, including work by Johns Hopkins University researcher M. Harvey Brenner, who suggested the downturns of the early 1970s and 1980s harmed health.

But Ruhm, a researcher at the University of North Carolina-Greensboro, worked with data from 1972 to 2000 and said his numbers suggest the reverse of Brenner’s conclusions, with two big caveats.

First, he readily admits mental health does not necessarily fit the same pattern. And the emphasis of the study is “temporary” economic downturns. In the long run, he says, economic growth is indisputably good for health.

“My strong belief is that moving from Bangladesh to the United States is very good for your health,” he said. “There’s no question about that.”

Admittedly, the data shows small changes, Ruhm said. He concluded an increase of 1 percent in a state unemployment rate reduces smoking, obesity and physical inactivity rates by 0.6 percent, 0.3 percent and 1.8 percent, respectively.

Such studies demonstrate the growing interest of economists in questions of whether people behave rationally when it comes to their well-being.