Prophylactic Laws

 by Michael C. Dorf

Scholars and jurists debate the legitimacy of the practice by which courts create so-called prophylactic rules that go beyond what the written law strictly requires. The best-known examples of rules that some people regard as prophylactic are the Fourth Amendment exclusionary rule and the Miranda warnings designed to protect against the inherent coerciveness of custodial interrogation. Some scholars and jurists view these rules as prophylactic. In this view, the rules go beyond what the Fourth and Fifth Amendments respectively require in order to prevent violations of those amendments. Whether to classify these rules as prophylactic is controversial, as is the authority of courts to fashion prophylactic rules at all.

Were I writing today about judge-made prophylactic rules, I would now discuss the various opinions in the 2000 SCOTUS decision in Dickerson v. US (which confusingly referred to the Miranda warnings as a "constitutional rule," even as prior cases that seemingly remained good law treated it as prophylactic), and my take on that decision in an article I co-authored with Prof Barry Friedman. However, today I want to discuss a cousin of prophylactic rules--a phenomenon that is both more common and less controversial.

In my Verdict column this week, I discuss Shinzo Abe's legacy, in particular his failed effort to repeal or dramatically scale back Article 9 of the Japanese Constitution, which forbids a military. I note that one argument Abe and others offer is that Japan has been in de facto breach of Article 9 for decades, because its "self-defense forces" are a military in all but name. Thus, these reformers argue, it would be more honest to acknowledge as much rather than to continue to violate the constitution. I reply that this logic is flawed; it assumes that just because there are widespread violations of Article 9, it has no impact. Japan might be still more militaristic without Article 9. To paraphrase Michelle Obama, things can get worse.

Seen in this perspective, Article 9 has at least one important characteristic it shares with prophylactic rules in constitutional law: It goes further than the core justification in service of that justification. Some further examples will flesh out what I mean by calling Article 9 a prophylactic law.

Start with a mundane case. In many US jurisdictions, the speed limit on a non-interstate highway is 55 miles per hour. Drivers routinely travel on such highways at speeds in excess of 60 mph. Although the exact custom varies from place to place, in general one assumes that if one does not exceed the speed limit by 10 mph or more, one will not receive a ticket. Now someone might say that this is harmful. Having a law on the books and even posted on signs that everyone knows is not the "real" law breeds disrespect for the law. Wouldn't it be better simply to raise the speed limit to 65 mph and instruct the highway patrol officers to enforce that limit strictly?

The answer is almost surely no. Whatever the speed limit, strict enforcement--in the sense of ticketing people who drive just slightly over it--will not make sense. When not using cruise control (which is not appropriate in many contexts), even a good driver's speed will fluctuate a bit. In addition, safety will sometimes require exceeding the speed limit temporarily, as when passing a slow-moving vehicle and suddenly seeing traffic in the other direction. Thus, unless they are using tickets as a revenue-raising device, highway patrol officers will necessarily allow drivers a bit of leeway. That practice is in fact the source of the informal norm that one can modestly exceed the speed limit without legal jeopardy. Raising the speed limit so that the law on the books catches up with the law on the streets will simply reset the law on the streets higher. If all other amps went to 11, Nigel's would go to 12. 

Treble damages are another familiar example. The law sometimes authorizes plaintiffs to collect treble damages, even though that provides them with a windfall. Nonetheless, treble damages can be justified as a means of over-deterring acts that would otherwise be under-deterred because difficult to detect or prove. Very severe criminal penalties for difficult-to-detect crimes would serve the same purpose, although our sense of distributive justice and the notion that the punishment should fit the crime cut against the use of a deliberately excessive penalty.

Here's yet another, albeit highly controversial, example. Consider the absolute ban on torture. You might support it because you think (as I do) that torture is always immoral. Suppose, however, that you think that the optimal amount of torture isn't zero but just a little bit more than zero because it could be justified in a rare but true ticking-bomb scenario. You might nonetheless worry that if the law allows any torture at all, the authorities responsible for public safety will act overzealously and start hearing ticking bombs where there are none. Meanwhile, an absolute rule of no torture at all ever would not overdeter. In a doomsday scenario in which torture is really what is needed to save the population (if one could know such a thing), one might expect the authorities to break the law and deploy torture anyway; they will count on jury nullification or a pardon. Or they will be willing to accept a risk of post-hoc punishment in order to save numerous lives. Thus, even if the optimal amount of torture is slightly more than zero, an absolute prohibition will bring us closer to that optimal amount than would any kind of allowance.

I suspect that the foregoing examples barely scratch the surface. A wise law maker will consider not only the question what is the ideal outcome--whether the size of the military, how fast people drive, how much tortfeasors should pay in damages, or how much torture there should be--but also how to write the substantive and remedial aspects of the law to get closest to that ideal outcome in light of enforcement gaps.