It is seemingly public opinion that severe and harsh sentences are required to prevent future crime. Almost every week, I hear someone say, “If penalties were harsh(er), people wouldn’t commit crimes.” This concept of affecting behaviour with punishment is referred to, in sentencing law, as ‘deterrence’ and has been a purpose in sentencing law for 100’s of years.

Within ‘deterrence’, there are two separate, but related, concepts:

1. Specific deterrence: This is focused on the individual offender. The idea is that if an individual is punished (severely/sufficiently), then the consequences of that individual’s actions will be instilled and that individual will be discouraged from committing future criminal acts.
2. General deterrence: This is focused on the general population. The idea is that if punishments are public and well-known, then the rate of crime will decrease, as other individuals, who see/hear about the punishments, will be deterred from committing crimes themselves.

Deterrence is based on the premise that humans are ‘rational’ and weigh the advantages and disadvantages of their actions. As a result, the pain of punishment must be equal to or more than the pleasure/benefits of crime in order to deter the public/individual from choosing to commit a crime.

However, does deterrence actually work? Short answer: no (with some shades of grey).

There is a growing acceptance that people commit crimes for reasons other than some rational decision-making process; people also commit crimes for psychological, social, or economic reasons. At least for me, I am sceptical (which is an understatement) that people think to themselves, “I choose to assault this person because the penalty does not currently outweigh the benefits of assaulting this person”. I am more inclined to believe that an assault would occur because of some psychological/social reason.

Also, if punishment actually deters people from re-offending, then the imposition of (arguably severe) penalties would prevent those same people from committing future crime. However, in 1999, there was an analysis of over 50 studies (involving over 336,000 offenders), which showed that prison sentences do not decrease recidivism (rate of re-offending); if anything, prison sentences actually produce an increase in recidivism; discrediting the idea of specific deterrence.

How about the deterrent effect on the general population? Does punishment of other offenders really deter the public from committing crimes themselves? Well, there isn’t a clear answer. There have been studies done on this issue, but there is no convincing evidence, either way, on overall (general) deterrent effect.

So, what do we know? What has actually been shown to be effective? Well, it has been found that the deterrent effect exists more with the certainty of punishment (probability of being caught) than the severity of punishment. So, if we want to reduce crime, measures should be taken to ensure that more offenders are caught (and subsequently prosecuted), rather than making amendments to the Criminal Code, creating harsher sentences. Besides, how many people have actually read the Criminal Code and know the penalties? Probably not many.