And I have issues with Freakonomics: they excel at doing a surface-level read of research, finding something to pick at, blow it completely out of proportion and sit back feeling clever about themselves. They're asses. That study, for example: Daycare cost: $380/mo = 8.5h/day x 5 days x 4 weeks = 170hrs = $2.23/hr Fine: $2.71 per child for any infraction over 10 minutes See, and none of that comes up when the Freakonomics guys bring it up. They just say "a small fine." They don't say "more than the hourly rate if you're 11 minutes late." It's like the serfs in the middle ages who went on pillaging sprees as soon as they were guilty of a nominal crime: if you're going to be executed anyway, might as well make it worth it. Know how many times I've been 11 minutes late to pick up my daughter? If you're going to hit me with the hourly for 11 minutes but nothing more for an hour or two, I'm getting some errands done. After all, I'm paying for it. These are the sorts of things Kahneman and Ariely study, but the Freakonomics guys just go "herp derp academics are stupid just look at this double-digit n study done out of that bastion of behavioral economics, UC San Diego!"
I think your concern about Levitt and Dubner is legitimate, though it would be more so if they published in Nature rather than blogging to Paul Krugman's audience. The authors of the daycare study described the fine as "relatively small but not insignificant." Whatever the size of the fine, it still prompts the question of why customers consume more of a service when the price changes from zero to something positive. The answer seems to be that a monetary incentive drowns out non-monetary incentives, like guilt. As Dan Ariely puts it in Chapter 5: I give Freakonomics credit for tricking people like me into realizing that economics is pretty interesting. Sumo wrestlers cheat, prostitutes use pricing strategies, drug empires operate like corporate empires. The ideas that incentives matter and unintended consequences are ubiquitous are important and ought to be popularized. And Iran is, therefore, the case study. Apparently at one point there was a waiting list for kidneys in Iran: the donors had to wait for a ready recipient.the theory of demand is a solid one—except when we're dealing with the price of zero. Whenever the price is not part of the exchange, social norms become entangled.
Kidney sales are legal in Iran.
Making you realize that economics is interesting is fine. They stop the minute they've built up a shaky case that they have the answers, though. "There is no Kitty Genovese effect." "Global warming is solved." "The possession effect doesn't exist." They're asses.