10. Less Obesity

People walk more, bike more and eat out less when gas is pricey. A permanent $1 hike in prices may cut obesity 10%, saving thousands of lives and billions of dollars a year, estimates Charles Courtemanche, an assistant professor of economics at the University of North Carolina at Greensboro. At Orange Cycle, the largest bike store in Orlando, Fla., sales of upright urban bikes from March to June rose 57% compared with the same period last year. The shop was around for the 1970s gas crisis too, but this feels different, says co-owner Deena Breed. "I don't think it's just gas," she says. "It has to do with weight, exercise, community — a general sense of not being so wasteful."

— With reporting by Maya Curry

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