Does the death penalty prevent future crime?
We are scared. Surveys find that the fear of crime is high and perhaps rising. So the question of prevention is important.
General deterrence is the idea that punishing an offender "deters" others from committing similar crimes. But does the threat of the death penalty actually discourage others from killing and thus make us safer? If so, does it do so significantly better than other forms of punishment?
Dozens of studies have examined the relationship between murder and the death penalty in Canada, the United States and elsewhere. They have compared murder rates in areas with the death penalty to those in areas without the death penalty. They examined what happened to murder rates when the death penalty was added or removed in various areas and countries.
None of these studies, however, has been able to establish that the death penalty results in lower murder rates or that the abolition of the death penalty increases murder rates.
If the death penalty deters, the deterrent effect is so small that even the most sophisticated attempts have been unable to measure it.
The vast preponderance of evidence suggests that the death penalty is no more effective than imprisonment in deterring others from committing violent crime.
Since Canada abolished the death penalty in 1976, substituting mandatory minimum prison sentences, the homicide rate has actually fallen by 27%. This pattern also has been observed in France and elsewhere.
Actually, the death penalty may have an effect that is the opposite of what is intended. After John Spenkelink was executed in Florida homicides seemed to rise, and observers have noted the same phenomenon in other circumstances.
Some recent studies seem to substantiate that pattern. One study in New York suggests that an execution will result in two or three extra homicides in the following months within that state alone, and possibly more in the entire country.
Rather than preventing violence, capital punishment may have a "brutalizing effect" that increases the level of violence in our society. It may in fact raise, not lower, murder rates.
How could the threat of death fail to prevent -- and possibly even cause -- violence? To understand this phenomenon, we must look at the theory of general deterrence, especially as it relates to the death penalty.
The idea of deterrence assumes that:
1. Each of us decides our actions by weighing the cost of these actions against the benefits. When the cost -- in this case the threat of death -- outweighs the potential benefits, we are discouraged from committing crimes. Crime is the result of conscious, rational choices.
2. People have a good idea of costs and a high degree of certainty that they will suffer the costs.
3. The consequences are seen as a significant cost at the time of the act.
4. A potential offender identifies with those being punished.
These assumptions of...