Usually, when we talk about changing the way people behave, we also talk about changing incentives. If we want motorists to conserve gas, we consider raising gas prices. It we want to encourage welfare families to stay together, we discuss changes in welfare rules. Most U.S. high school students have little incentive to work hard and get good grades, and some school districts have begun trying to change this by offering rewards and prizes for kids who improve their school performance.

A couple of months ago, I heard a school administrator describe his school's incentive program on the radio. The school offered all kinds of prizes for getting good grades and coming to school regularly. There was even a new car, donated by a local dealer, that would go to a student with good attendance -- and the lucky number in the incentive program's car lottery. The program was relatively new, but the administrator said attendance had improved. He was hopeful that kids would get excited about learning, too. But on the same show, a critic called the school's incentive program "desperate and sad." Many people would agree with him.

People who are offended by extrinsic incentives like cars or pizza parties say they are nothing more than bribes that reward kids for what they are supposed to do anyway. People also object on practical grounds: They think prizes for performance won't work -- at least not in the long run. Once the pizzas with double cheese stop coming, youngsters will stop reading Dickens or working on their science projects. The incentives won't do a thing to change their attitude toward schoolwork.

These objections ignore a lot of experience we've already had with using incentives to motivate young people. When I was a kid, my parents offered me incentives -- like stamps for my album -- to encourage me to study hard and get good grades. There was a different incentive every report period; and my parents also told me I'd be deprived of something if my grades weren't good. Bribery? Sure, but parents have been getting good results with it for years. Often kids who have to be bribed end up getting hooked on reading or chemistry or playing the piano.

Those who say that reading will stop when the pizza does may be wrong. Some jobs are inherently unpleasant. Suppose you offer incentives to increase the number of tons of garbage your workers move each day. If the extrinsic incentives are attractive enough, workers will move more garbage. But the moment you reduce the incentives, the tonnage will be back where it was. On the other hand, if you offer incentives to people who read poorly, these incentives might get many of them to the point where they read well and enjoy reading. And they won't need sticks or carrots anymore.

So there are two questions to ask about incentives. Is what we're trying to get people to do enjoyable enough so that, once they reach a certain level, they will need no further incentives? When we're talking about what kids are supposed to learn in school, the answer is, or should be, yes. The second question is, does the incentive work? Will it really get kids to work harder and learn more?

Some incentives that we think will work don't. A couple of years ago, people in West Virginia decided to attack their dropout problem by lifting the driver's licenses of kids who left school. They reasoned that young people would be very eager to hang on to their licenses, and this would be an incentive to stay in school until they graduated.

The first year, the results looked good -- nearly 33 percent fewer students dropped out than had the previous year. But the second year, the number of dropouts increased by the same percentage. When Rutgers sociologist Jackson Toby and David Armor asked why, they found that the first year was a fluke; the majority of potential dropouts did not even have driver's licenses. Also, Toby and Armor decided, the ones who did probably thought staying in school was worse than losing their license.

On the other hand, a high school in Michigan that has had an elaborate system of incentives in place since 1989 reports that its program has been very successful. ACT scores have increased 12 percent; average daily attendance has increased 6 percent; and the number of students sent to the principal's office to be disciplined has declined an amazing 60 percent. An administrator who is quoted in the Wall Street Journal (January 29, 1992) says that the incentives have led to a big improvement in the school's atmosphere: "Three years ago, this was an intimidating place to be. Now there's a sense of pride and security. Now students want to be here and feel they're not losers."

Figuring out which incentives will work is not easy, and it often takes time. Different incentives work in different situations. The driver's license scheme that failed in West Virginia might succeed elsewhere -- where more kids on the borderline had diver's licenses. And different incentives work for different people, which may explain why parents, who can tailor incentive to their children's likes and dislikes, are often successful. Also, some incentives work for a while and then stop working. Students in that Michigan school may tire of the prizes they are being offered, and if the people in charge want to keep them motivated, they may have to devise a new array of incentives. Some people are all for the idea of offering kids a free school jacket in return for trying harder in school; other people are outraged. But successful incentives take many different forms We should be encouraging schools to experiment with incentives, not rejecting their efforts before we can see if they work.