7. The Deterrence Argument
Scientific studies have consistently failed to find convincing evidence that the death penalty deters crime more effectively than other punishments. The most recent survey of research findings on the relation between the death penalty and homicide rates, conducted for the United Nations in 1988 and updated in 2002, concluded: "… it is not prudent to accept the hypothesis that capital punishment deters murder to a marginally greater extent than does the threat and application of the supposedly lesser punishment of life imprisonment."
(Reference: Roger Hood, The Death Penalty: A World-wide Perspective, Oxford, Clarendon Press, third edition, 2002, p. 230)
8. Effect of Abolition on Crime Rates
Reviewing the evidence on the relation between changes in the use of the death penalty and crime rates, a study conducted for the United Nations in 1988 and updated in 2002 stated: "The fact that all the evidence continues to point in the same direction is persuasive a priori evidence that countries need not fear sudden and serious changes in the curve of crime if they reduce their reliance upon the death penalty".
Recent crime figures from abolitionist countries fail to show that abolition has harmful effects. In Canada, for example, the homicide rate per 100,000 population fell from a peak of 3.09 in 1975, the year before the abolition of the death penalty for murder, to 2.41 in 1980, and since then it has declined further. In 2003, 27 years after abolition, the homicide rate was 1.73 per 100,000 population, 44 per cent lower than in 1975 and the lowest rate in three decades.
(Reference: Roger Hood, The Death Penalty: A World-wide Perspective, Oxford, Clarendon Press, third edition, 2002, p. 214)