Unexpected Consequences # 1

One thing that Doug and I stress in the course "The Economics of Compassion" is that intentions can be different than results, particularly if the person attempting to "do good" doesn't take account of things such as a ) complicated general equilibrium effects in the underlying science, medicine, engineering, etc. or b) the fact that human beings change their behavior in response to incentives. I thought it might be fun to begin a series of short posts at more frequent intervals that illustrate this point. Today, thanks to Instapundit, I've linked to an article from the St. Petersburg Times that investigates the question as to whether "red light cameras" cause more accidents than they prevent. If so, the reason is almost certainly that driver behavior changes in response to the incentives posed by the cameras.