THE CAR OF THE FUTURE - The Power Surge: Energy, Opportunity, and the Battle for America's Future - page 138

h e claim that ei ciency does not actually reduce resource consump-
tion became known as the Jevons Paradox, and more than a century
at er his death it lives on in i ghts over the true promise of greater
ei ciency in American energy use. “Mr. Wizard, meet Mr. Jevons,” one
prominent skeptic of improved fuel ei ciency wrote mockingly on his
blog. 96 Yet reality appears to disagree with the strong skeptics.
When it comes to cars, the naïve invocation of the Jevons Paradox
leads to a simple conclusion: if all Americans start buying new cars
that are twice as fuel ei cient as their old ones, they will drive more,
because the cost of driving will have been cut in half. In the worst
case, they will drive twice as much, entirely negating the value of the
ei ciency bump.
h is logic is deeply l awed. It might sometimes seem as if the most
expensive part of driving is the cost of gasoline—at er all, every time
you i ll up, the ot en staggering cost is right in your face. But the big-
gest cost of driving is actually the value of your time. Say you drive
your car, which gets twenty miles per gallon, a distance of ten miles.
h at uses half a gallon of gas; if gas costs four dollars a gallon, you're
out two bucks. Now imagine you're driving at twenty miles an hour, so
your trip takes thirty minutes. For the typical American (who makes
about twenty dollars an hour), that much time is worth ten dollars. h e
biggest cost of your trip isn't the gas: by a factor of i ve-to-one, it's you.
h is is why, if you were to replace your car with one that was twice as
ei cient, you wouldn't drive much more. 97 It's not surprising that when
researchers carefully study how greater ei ciency af ects driving habits
in the real world, they i nd only a small ef ect: a person might drive
10 percent more as the fuel ei ciency of their car doubles, but most
of the savings, including in greenhouse gas emissions, can be taken to
the bank. 98

T here is a dif erent problem when it comes to cut ing oil consump-

tion by using more biofuels: the biofuels themselves can increase
emissions. For a long time, the knock on corn ethanol focused on a
simple problem: it can take as much energy to make a gallon of ethanol
as you get out. h e corn, of course, harnesses energy from the sun that
isn't going to be used for anything else. But running the farm where it