The Volokh Conspiracy

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Slippery Slope Arguments

Being Alert to the Slippery Slope Risk + Constitutions as Tools for Preventing Slippery Slope Inefficiency


[This month, I'm serializing my 2003 Harvard Law Review article, The Mechanisms of the Slippery Slope; in last week's posts, I laid out some examples, definitions, and general observations, and turned to a specific kind of slippery slope mechanism—cost-lowering slippery slopes. This week, I've been elaborating on that; tomorrow, I'll shift to some other related mechanisms.]

The analysis so far suggests that decisionmakers—legislators, voters, advocacy groups, or opinion leaders—should consider how proposed government actions would change the costs of implementing future actions, in particular:

  1. How would this government action provide more information to the government (for example, who owns the guns), and what other actions (for example, seizing the guns) would be made materially cheaper by the availability of this information?
  2. How would this government action provide more tools to the government (for example, video cameras), and what other actions (for example, automated face recognition or videotape archiving) would be made cheaper by the existence of these tools?
  3. How would this government action provide more experience to the government in doing certain things, and what other actions would this extra experience make less risky and thus more politically appealing?
  4. How would this government action provide more legal power to the government (for example, the power to search people's homes), and what other actions would this extra grant of power make possible or make easier?

Opponents of B thus can't simply console themselves with the possibility that a line between A and B can logically be drawn, dismiss the slippery slope concern as being that "we ought not make a sound decision today, for fear of having to draw a sound distinction tomorrow," or argue that

[s]omeone who trusts in the checks and balances of a democratic society in which he lives usually will also have confidence in the possibility to correct future developments. If we can stop now, we will be able to stop in the future as well, when necessary; therefore, we need not stop here yet.

There's a different "we" involved: those who support A but oppose B should fear that if they vote for A now, such a vote may lead others to vote for B later—and that though a logical line could be drawn between A and B (yes cameras, no archiving, no face recognition), most voters will decide to draw the line on the far side of B rather than on the near side. Even those who generally trust that their society is democratic can therefore rationally oppose a decision that they like on its own, for fear that it will lower the cost of another decision that they dislike and thus make that decision more likely.

And the examples we've discussed illustrate something I call "the slippery slope inefficiency": even if most voters believe decision A (for example, gun registration) is good policy on its own, A may be rejected because enough of those voters fear that A will lead to B (gun prohibition), which they oppose. {Even some gun rights supporters, for instance, might (whether or not correctly) think that registration may help solve some crimes without materially burdening people's ability to defend themselves, so long as registration doesn't lead to confiscation. But especially given that the crime-fighting effects of registration systems seem to be quite modest, even a small possibility that registration may facilitate confiscation could reasonably lead gun rights supporters to oppose registration.}

And the examples point to one possible way of preventing the inefficiency: the recognition of constitutional rights that would prevent B, such as a non-absolute right to own guns. Once this constitutional precommitment makes B much less likely, opponents of B have less to fear (to the extent they trust the courts) and can therefore support A or at least oppose it less.

Constitutional constraints are thus not only legislation-frustrating (because they prohibit total bans on guns), but also in some measure legislation-facilitating (because some voters may support more modest gun controls, once they stop worrying that these controls will lead to a total ban). Changing a constitution to secure a right may therefore sometimes be good both for those who want to moderately protect the right and for those who want to moderately restrict it—though naturally much depends on how broad the right would be, and on how much political power the various groups have.

On the other hand, as we'll discuss soon, a constitutional right may also have attitude-altering effects that help cause slippage to greater and greater protection for the right. Judicial recognition of a right to bear arms may thus facilitate some compromise gun control proposals (A) because it will diminish some voters' concerns that A will lead to a total gun ban (B)—but recognizing the right to bear arms might eventually lead to A being undone, and to the law shifting back closer to the initial position 0, as judges or voters are influenced by the attitude-shaping force of the constitutional right. The long-term effects of any decision are not easy to predict, though understanding the slippery slope mechanisms should help us investigate the likelihood of such effects.