Freakonomics: “…In 1978, New York enacted its famous (and widely imitated) ‘pooper scooper’ law, and the city is plainly cleaner, poop-wise, than it was. But with a fine of just $50 for the first offense, the law doesn’t provide much financial incentive to pick up after your dog. Nor does it seem to be vigorously enforced. Let’s pretend that 99 percent of all dog owners do obey the law. That still leaves 10,000 dogs whose poop is left in public spaces each day. Over the last year, the city ticketed only 471 dog-waste violations, which suggests that the typical offender stands a roughly 1-in-8,000 chance of getting a ticket. So here’s a puzzle: why do so many people pick up after their dogs? This would seem to be a case in which social incentives – the hard glare of a passer-by and the offender’s feelings of guilt – are at least as powerful as financial and legal incentives.

If social forces get us most of the way there, how do we deal with the occasional miscreant who fails to scoop?” (New York Times Magazine)