Many crimes, especially violent crimes and property crimes, are human rights violations. The fact that theft, assault, violent attack and murder are crimes in most if not all national legal systems, indicates a high degree of normative consensus on the importance of a subset of human rights, namely the right to life, the right to property and the right to physical security.
Moreover, there’s also a high degree of consensus across different national legal systems as to the best way to react to these rights violations and to stop them from happening in the future: isolate the perpetrators in prisons. We believe that this will prevent crime in three ways:
- It stops the criminal from re-offending during the period of his/her isolation.
- It stops the criminal from re-offending after the period of his/her isolation.
- It stops other people from following his/her example.
The last two bullet points are what’s called “deterrence”. We tend to believe that this deterrence effect correlates with the severity of the punishment. More years in prison means more deterrence. More brutal punishments – such as capital punishment – means even more deterrence. The belief in this correlation between degree of deterrence and degree of punishment rests on the “rational actor hypothesis”: people will take only those actions that produce more benefits than costs. If the punishment for a certain type of crime imposes a much lower cost on the potential criminal than the benefits the result from the crime – for instance a few weeks in prison for a theft worth several millions of dollars – and if the chances of being caught are reasonably low, than a “rational actor” is likely to become a criminal. Deterrence is therefore a function not only of the severity of the punishment but also of the probably of getting caught.
There are three problems with deterrence understood like this.
Many people don’t fit the rational actor description. They don’t make cost-benefit analyses before engaging in actions, especially not when crime is concerned (and certainly not in cases of certain types of crimes, such as “crime passionnel”).
Reductio ad absurdum
There’s an element of “reductio ad absurdum” in deterrence: if you want to deter certain types of crimes, especially crimes with very high potential benefits, you have to impose very high costs. Hence you may find that your logic leads you into acceptance of very brutal punishments: e.g. very painful, prolonged and public types of capital punishment, the killing of the family and friends of criminals etc. The danger with all cost-benefit logic in human affairs – and with utilitarian philosophies in general – is that you wind up accepting the sacrifice of some for the larger benefit of society as a whole. Rawls called this the failure to take distinctions between persons seriously. Utilitarianism means
extending to society the principle of choice for one man, and then, to make this extension work, conflating all persons into one through the imaginative acts of the impartial sympathetic spectator. Utilitarianism does not take seriously the distinction between persons. John Rawls (source)
It seems that if you want to defend deterrence, you have to stop at some point and accept that there are limits to it. There are certain things you just can’t do to people, and no amount of deterrence or other benefits can justify doing these things.
Doesn’t work, unless…
It’s not beyond doubt that deterrence works, probably in part because of the first point. There’s solid evidence to the contrary in the case of capital punishment (see here). But also for crime in general and prison sentences there’s doubt:
Although long sentences are now common and the incarceration rate is five times what it was during most of the 20th century, the crime rate is still two and a half times the average of 1950-62. … most criminals are not the dispassionate rational actors who populate standard economic models. They are more like impulsive children, blinded by the temptation of immediate reward and largely untroubled by the possibility of delayed or uncertain punishment. (source)
Detention only seems to work when the odds of apprehension and punishment are very high.
The evidence suggests that when hardened criminals are reasonably sure that they will be caught and punished swiftly, even mild sanctions deter them. But not even the prospect of severe punishment is effective if offenders think they can get away with their crimes. (source)
This would seem to undermine the argument for capital punishment. Of the two elements that are believed to cause the deterrent effect, only the odds of getting caught seem to matter, not the severity of the punishment. Hence, capital punishment is useless. What counts is the odds of getting caught, not what happens when you’re caught. In general, people take costs that are relatively modest but immediate and certain much more seriously than higher costs that may or may not happen in the longterm.
Experimenters have found, for example, that even long-term alcoholics become much less likely to drink when they are required to receive a mild electric shock before drinking. Many of these same people were not deterred by their drinking’s devastating, but delayed, consequences for their careers and marriages. (source)