Unintended Consequences, Law of

Sources of Unintended Consequences

Merton's article categorizes some of the principal sources of unintended consequences. They include ignorance, error, “imperious immediacy of interest” whose urgency crowds out consideration of other consequences, and “basic values” that mandate particular actions irrespective of their consequences. Last—and most interesting—is the reflexive nature of predictions about social conduct. The prediction itself may affect behavior in such a way as to make the prediction selfdefeating or self-fulfilling. (Here, Merton anticipates his own subsequent work on the self-fulfilling prophecy.) As Merton says, every prediction includes a tacit “other-things-equal” clause, but, in the case of a prediction about social conduct, other things won't be equal because the actor has introduced a new “other thing”—his prediction. This is not true of prediction in fields that do not pertain to human conduct; the prediction of the return of Halley's Comet does not in any way influence its orbit.

Unintended Consequences and the Domain of the Social Sciences

If unintended consequences have been enshrined as a “law” of social science, it is because they define the agenda or subject matter or inquiry at the heart of the social sciences. Karl Popper has argued that the characteristic problems of the social sciences arise only out of our wish to know the unintended consequences, and more especially the unwanted consequences, which may arise if we do certain things. Likewise, Friedrich Hayek has contended that the function of social science is to explain how conscious, purposeful human action can generate unintended consequences through social interaction.

In economics, the law of unintended consequences is ubiquitous. It is exemplified by concepts like Adam Smith's invisible hand and moral hazard (the fact that insuring against an undesired event may make it more likely). In sociology, it is illustrated by Robert Michels's “iron law of oligarchy,” Max Weber's account of how Protestant thrift and industry were self-defeating because they resulted in the accumulation of wealth that, in turn, corroded those same virtues, and Karl Marx's account of how the bourgeoisie inevitably produces its own gravediggers.

Without unintended consequences, the social sciences as we know them would be inconceivable. In their place there would be psychology. If outcomes were always intended, then intentions (and the needs, hopes, and motives that underlie them) would be the only object of social scientific interest because they would entirely explain social phenomena. Popper calls this the error of “psychologism”—namely, the view that social laws must ultimately be reducible to psychological laws, since the events of social life, including its conventions, must be the outcome of motives springing from the minds of individual men and women.

...