Lecture Extender Examples 511
The results were consistent with the rationality assumption. One-third of the students in the group that
was paid regardless of performance picked all of the gambles correctly. In the second group, for which
performance was distinctly rewarded, two-thirds of the students had no errors in making their
calculations.
Incentives and Childhood Obesity
Children who gain weight eat more calories than they use up each day. The ones who gain weight the
fastest eat relatively more high-calorie foods such as hamburgers, French fries, and other fast foods. They
also exercise less, preferring to spend more of their time watching TV and playing video games rather
than playing out doors and participating in sports.
Traditionally, mothers have taken responsibility for making the choices about what foods children eat and
the scope of their outdoor activities. As compared to the 1960s, when about one-half of mothers worked
outside the home, more than three-fourths do so today. These mothers have less time to keep their
children from eating too much, e.g., in the hours after school before getting home from work, and to take them
to playgrounds to exercise. This helps explain why only 8 percent of children whose mothers have never
worked outside the home are obese as compared to 17 percent among children whose mothers work full-
Incentives and the Internet
It is worth examining the idea that changes in incentives cause people to change their behavior. In recent
years, the cost of some types of high-speed Internet service has declined to as little as $20 per month for
unlimited access to the Internet. This means that people who use their high-speed connection primarily
for surfing the Web for information and e-mail pay exactly the same amount per month as do gamers and
people who download music and videos. The first group uses very little bandwidth, and the second group
uses very high amounts of bandwidth. Recently, some Internet service providers (ISPs) have put forth the