WASHINGTON – Today’s high gas prices could reduce auto deaths by nearly a third as driving decreases, with the effect particularly dramatic among price-sensitive teenage drivers, the authors of a new study said.

Professors Michael Morrisey of UAB and David Grabowski of Harvard Medical School found that for every 10 percent increase in gas prices there was a 2.3 percent decline in auto deaths. For drivers ages 15 to 17, the decline was 6 percent, and for ages 18 to 21, it was 3.2 percent.

The study looked at fatalities from 1985 to 2006, when gas prices reached about $2.50 a gallon. With gas now averaging over $4 a gallon, Morrisey said he expects to see a drop of about 1,000 deaths a month.

With annual auto deaths typically ranging from about 38,000 to 40,000 a year, a drop of 12,000 deaths would cut the total by nearly a third, Morrisey said.

“I think there is some silver lining here in higher gas taxes in that we will see a public health gain,” Grabowski said. But he cautioned that their estimate of a decline of 1,000 deaths a month could be offset somewhat by the shift under way to smaller, lighter, more fuel-efficient cars and the increase in motorcycle and scooter driving.

Morrisey said the study also found the “same kind of symmetry” between gas prices and auto deaths when prices go down.

“When that happens we drive more, we drive bigger cars, we drive faster and fatalities are higher,” he said.

Morrisey and Grabowski presented their findings to a meeting of the American Society of Health Economists in Raleigh-Durham, N.C., last month. The study was funded by the Robert Wood Johnson Foundation.