If the goal is to cut greenhouse gas emissions, creating more energy efficient technologies may backfire, say economists, since more energy efficient products will encourage more consumption. "The problem is known as the energy rebound effect. While there’s no doubt that fuel-efficient cars burn less gasoline per mile, the lower cost at the pump tends to encourage extra driving. There’s also an indirect rebound effect as drivers use the money they save on gasoline to buy other things that produce greenhouse emissions, like new electronic gadgets or vacation trips on fuel-burning planes."