On his blog, Levitt cites a study he and three colleagues published (as an NBER working paper). The researchers rewarded kids for trying hard on an exam. As Levitt notes, the goal of previous research has been to get kids to learn more. That wasn't the goal here. It was simply to get kids to try harder on the exam itself, to really show everything that they knew.
Among the findings: (1) it worked. Offering kids a payoff for good performance prompted better test scores; (2) it was more effective if, instead of offering a payoff for good performance, researchers gave them the payoff straight away and threatened to take it away if the student didn't get a good score (an instance of a well-known and robust effect called loss aversion); (3) children prefer different rewards at different ages. As Levitt puts it "With young kids, it is a lot cheaper to bribe them with trinkets like trophies and whoopee cushions, but cash is the only thing that works for the older students."
There are a lot of issues one could take up here, but I want to focus on Levitt's surprise that people don't like this plan. He writes "It is remarkable how offended people get when you pay students for doing well – so many negative emails and comments." Levitt's surprise gets at a central issue in the application of science to education.
Scientists are in the business of describing (and thereby enabling predictions of) the Natural world. One such set of phenomenona concerns when students put forth effort and when they don't.
Education is a not a scientific enterprise. The purpose is not to describe the world, but to change it, to make it more similar to some ideal that we envision. (I wrote about this distinction at some length in my new book. I also discussed on this brief video.)
Thus science is ideally value-neutral. Yes, scientists seldom live up to that ideal; they have a point of view that shapes how they interpret data, generate theories, etc., but neutrality is an agreed-upon goal, and lack of neutrality is a valid criticism of how someone does science.
Education, in contrast, must entail values, because it entails selecting goals. We want to change the world--we want kids to learn things--facts, skills, values. Well, which ones? There's no better or worse answer to this question from a scientific point of view.
A scientist may know something useful to educators and policymakers, once the educational goal is defined; i.e., the scientist offers information about the Natural world that can make it easier to move towards the stated goal. (For example, if the goal is that kids be able to count to 100 and to understand numbers by the end of preschool, the scientist may offer insights into how children come to understand cardinality.)
What scientists cannot do is use science to evaluate the wisdom of stated goals.
And now we come to people's hostility to Levitt's idea of rewards for academic work.
I'm guessing most people don't like the idea of rewards for the same reason I don't. I want my kids to see learning as a process that brings its own reward. I want my kids to see effort as a reflection of their character, to believe that they should give their all to any task that is their responsibility, even if the task doesn't interest them.
There is, of course, a large, well-known research literature on the effect of extrinsic rewards on motivation. Readers of this blog are probably already familiar with it--if so, skip the next paragraph.
The problem is one of attribution. When we observe other people act, we speculate on their motives. If I see two people gardening--one paid and the other unpaid--I'm likely to assume that one gardens because he's paid and the other because he enjoys gardening. It turns out that we make these attributions about our own behavior as well. If my child tries her hardest on a test she's likely to think "I'm the kind of kid who always does her best, even on tasks she don't care for." If you pay her for her performance she'll think "I'm the kind of kid who tries hard when she's paid." This research began in the 1970's and has held up very well. Kids work harder for rewards. . . until the rewards stop. Then they engage in the task even less than they did before the rewards started. I summarized some of this work here.
In the technical paper, Levitt cites some of the reviews of this research but downplays the threat, pointing out that when motivation is low to start with, there's not much danger of rewards lowering it further. That's true, and I've made a close argument: cash rewards might be used as a last-ditch effort for a child who has largely given up on school. But that would dictate using rewards only with kids who were not motivated to start, not in a blanket fashion as was done in Levitt's study. And I can't see concluding that elementary school kids were so unmotivated that they were otherwise impossible to reach.
In addressing the threat to student motivation with research, Levitt is approaching the issue in the right way (even if I think he's incorrect in how he does so.)
But on the blog (in contrast to the technical paper), Levitt addresses the threat in the wrong way. He skips the scientific argument and simply belittles the idea that parents might object to someone paying their child for academic work. He writes:
Perhaps the critics are right and the reason I’m so messed up is that my parents paid me $25 for every A that I got in junior high and high school. One thing is certain: since my only sources of income were those grade-related bribes and the money I could win off my friends playing poker, I tried a lot harder in high school than I would have without the cash incentives. Many middle-class families pay kids for grades, so why is it so controversial for other people to pay them?
I think Levitt is getting "so many negative emails and comments" because he's got scientific data to serve one type of goal (get kids to try hard on exams) the application of which conflicts with another goal (encourage kids to see academic work as its own reward). So he scoffs at the latter.
I see this blog entry as an object lesson for scientists. We offer something valuable--information about the Natural world--but we hold no status in deciding what to do with that information (i.e., setting goals).
In my opinion Levitt's blog entry shows he has a tin ear for the possibility that others do not share his goals for education. If scientitists are oblivious to or dismissive of those goals, they can expect not just angry emails, they can expect to be ignored.