Discussions around the deterrent effect of capital punishment usually center on a wrong question. The question to be asked is not whether the death penalty deters would-be murderers, but whether it deters them more than the prospect of life imprisonment. The question is not whether the death penalty has a deterrent effect but whether it provides a unique and supreme deterrent, whether it is the most powerful and most effective of all deterrents. It seems

obvious that the death penalty cannot be justified on grounds of its deterring function alone unless and until it has been proven beyond a reasonable doubt that it supplies an additional increment of deterrence above and beyond the alternative which, in most jurisdictions, is life imprisonment. Has such a unique deterrent effect been unequivocally proven? The answer to this question is NO.

Early deterrence research failed to show any relationship between the abolition or reinstatement of the death penalty and homicide rates. Despite the fact that several different studies reached the same conclusion, namely that the death penalty has no noticeable effect on the rates of homicide, these studies were dismissed by retentionists as "extremely primitive statistically" and as having been done by "not very good statisticians". Retentionists, on the other hand, were quick to hail the one study that reached an opposite conclusion, namely the now famous Ehrlich study.¹⁴ They either failed to detect the flaws in Ehrlich's data and methodology or simply decided to ignore whatever defects the study suffered from.