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Slippery-Slope Logic

Richard Thaler with an interesting article in the New York Times on slippery-slope logic.

One pernicious category of imaginary risks involves those created by users of the dreaded “slippery slope” arguments. Such arguments are dangerous because they are popular, versatile and often convincing, yet completely fallacious.

A DirecTV ad humorously illustrates the basic form of slippery-slope arguments:

A foreboding announcer intones a list of syllogisms that are enacted on screen: “When your cable company puts you on hold, you get angry. When you get angry, you go blow off steam. When you go blow off steam, accidents happen.” Later, we reach the finale: “You wake up in a roadside ditch. Don’t wake up in a roadside ditch.”

Although this ad is intended to be funny, arguments that make no more sense can and do affect public policy. The idea is that while Policy X may be acceptable, it will inevitably lead to the terrible Outcome Y, so it is vital that we prevent Policy X from ever being enacted. The problem is that such arguments are often made without any evidence that doing X makes Y more likely, much less inevitable. What percentage of people who are left on hold on the telephone end up in a roadside ditch?

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Still curious? Thaler is the co-author of Nudge: Improving Decisions About Health, Wealth, and Happiness.