Unintended Consequences of Individual Behavior

Things do not always turn out the way we intend. Many events occur unintentionally. Sometimes, the causes are trivial, as when we press the accelerator instead of the brake or hit the “delete” button by mistake. Some mechanisms are more systematic, however. While there can hardly be a “general theory of unintended consequences,” one can at least begin to compile a catalogue. I consider cases in which the consequences are not only unintended, but also unforeseen. Foreseeable “side effects of action” are not intended for their own sake, especially if they are negative, but I shall not count them as “unintended consequences of action.”

Unintended consequences can arise from individual behavior as well as from social interaction. Beginning with the former, we can use a simple extension of the desire-opportunity framework that was set out in Chapter 9 (see Figure 18.1).

While actions are shaped by desires (or preferences), they can also shape desires. Thus in addition to the intended outcome of an action, there is sometimes an unintended one: a change of desire. Addiction is a good example. Under the influence of addictive drugs, people begin to discount the future more heavily, thus weakening the deterrence effect of the long-term harm from addiction. Had this effect been anticipated, it might have prevented the agent from embarking on the path to addiction, but typically it is not.