Skip to main content


Link Copied

Do tough sentences deter crime?

Penelope Gibbs
02 Jun 2016

Nearly half the British population supports the death penalty and two thirds agree with the argument that “the best way to reduce re-offending is to increase the deterrent effect of sentencing – by sending more offenders to prison, making prison life harder, making sentences longer, and making community punishments more demanding”.  But as Tom Gash points out in his excellent new book, Criminal- the truth about why people do bad things, there is little evidence that tough sentences do deter crime.

There is a deep-seated popular belief (found in our reframing research) that committing crime is a rational act – that criminals logically weigh up the chances of being caught and the severity of their punishment, against the gains to be made from committing a crime.  So most people think that crime is an individual, rational choice – thus if punishment is made more severe, potential criminals will make a different choice. This belief has led to a raft of tough on crime policies in USA, Canada and in the UK.  In 1993 Michael Howard, when Home Secretary, declared that prison works: “it ensures that we are protected from murderers, muggers and rapists – and it makes many who are tempted to commit crime think twice”. Since that time our prison population has doubled, fuelled for the most part not by sentencing more people to imprisonment, but by tougher sentences.  Average prison sentences have increased steadily (up four months vs twenty years ago) and continue to do so.

But as Tom Gash points out, there is plenty of evidence to show that tougher sentences have little impact on crime.  Finland in 1960s decided to reduce their prison population.  They removed nearly all fine defaulters from prison, then reduced the numbers of those imprisoned for theft, drink-driving and other non-violent crimes. Suspended sentences became the norm for first-time offenders who had been given prison sentences of less than two years.  Crime did in fact go up significantly from 1960 to the late 1980s, but it went up no more in Finland than in other Scandinavian countries, with low prison populations. Crime also went up steeply in USA where the prison population soared.

In America new tough laws were brought in, the toughest of which was the Californian three strikes rule which was introduced in 1994. It said that anyone convicted of two serious offences would be imprisoned for life on committing their third offence. This third offence did not need to be serious to count, so people ending up serving life sentences after lying on a driving theory test or shoplifting. If deterrent sentencing works, this draconian three strikes law should have prevented anyone affected committing that third crime.  But it didn’t.  An economic study concluded that people on two strikes were only 12.5% less likely to be arrested after the new law than before it.  Another study suggested that the threat of punishment might have encouraged two strikers to commit more serious third crimes as “rather be hanged for a sheep than a lamb”.

If you understand that crime is most often a spontaneous, reckless act, rather than a rational, considered choice, it makes sense that severity of punishment does not deter.  But the belief in the criminal as “rational actor” and the power of prison is very strong.  Let’s hope we can shift those beliefs.