If crime falls significantly you’d expect the prison population to fall too. That has happened in Scotland in recent years, but not in England and Wales.  Laudable though the fall is, should the Scottish prison population have fallen further still?  The Scottish prison population rose steeply through the 1990s and 2000s while crime was falling equally steeply. Researchers attribute the increasing use of prison to better clear-up rates for crimes and to sentencing policy – more crimes being punished with imprisonment and those imprisoned getting longer sentences. The same happened in England and Wales.

But the two nations began to diverge as soon as the SNP formed a majority government in 2011. From then on the Scottish prison population began to fall while that of England and Wales stayed more or less the same (and is now projected to rise). Since 2011 the Scottish prison population has fallen 8% but crime has fallen at a greater rate.  So what has driven the population down and what has prevented it falling further? (I talked this through with Scottish civil servants on my recent visit).

Drivers for increase

1. The clear up and conviction rates improved (then levelled off) so a higher proportion of crimes were ending up with a criminal sanction.
2. An increase in the average length of sentences for crimes like domestic burglary, domestic violence and murder – life sentences (as served) have increased from 10 years in 2000 to 18 years in 2012.

Drivers for decrease

1. The average length of prison sentence for serious violent offences and drugs offences has come down (unlike in England and Wales)
2. Reduced use of short prison sentences, particularly since a presumption against sentences under three months came into force. These sentences account for less than 5% of the prison population. But there’s probably also an indirect effect on prison numbers – using community sentences leads to lower reoffending.
3. Lower numbers on remand – probably because the presumption against short sentences is dissuading judges from using remand for less serious crimes. Judges don’t want to remand for a few weeks if the offender is likely to be in line for a community sentence.

So all is not rosy in the Scottish criminal justice garden. But there are significant differences between Scotland and England and Wales. Our sentence inflation has been and is worse – 31% increase in average sentence length 2007-2016 versus 26% in Scotland, our sentences are increasing in length every quarter whereas Scottish sentences have levelled off, and the difference in average prison sentence for some crimes is quite stark

• Fraud – average sentence 20.2 months in England and Wales vs 10.8 months in Scotland
• Criminal damage/vandalism and arson – average sentence 27.6 months in England and Wales vs 7.8 months in Scotland
• Drug offences – average sentence 20 months in England and Wales vs 15.6 months in Scotland.

People will accuse me of comparing apples and pears, but its worth making a rough and ready comparison. Are our drug offences on average so much more serious than those in Scotland? I doubt it. And the difference in average custodial sentence is enormous (though possibly not comparable) – 9.5 months in Scotland versus 16.2 in England and Wales. It would be worth someone doing a study comparing sentencing in England and Wales and Scotland.

Both nations need to watch their sentence inflation, particularly if crime begins to rise again. But at least Scotland has a falling prison population, has halted sentence inflation, and is planning something major to embed the trend – a presumption against using prison sentences under 12 months. This will transform the landscape through allowing prisons to concentrate on rehabilitation (short sentenced prisoners swallow up administrative resources), it will reduce overall prison numbers, and further discourage the inappropriate use of remand.

Sentence inflation is intriguing (in Scotland only for certain offences) – it is simply not credible that the offences in front of courts are so much more serious than they used to be. Rather it looks as though sentencing has got more severe, maybe due to political and public pressure.

This recent Scottish petition against the four year sentence for a 17 year old who killed a well known footballer shows that we all face a huge hurdle in persuading the public that prison does not work and more imprisonment does not work better.  The sentence was for culpable homicide, the Scottish equivalent of manslaughter. In contrast an English 15 year old who killed a child (Katie Rough) while very mentally ill was also convicted of manslaughter, but given a life sentence with a minimum term of five years.

I hope the Scots hold their nerve, both on the sentence of the 17 year old and on the presumption against 12 month sentences. England and Wales needs an example to follow of a nation with a similar criminal justice system which has succeeded in turning the punitive tide.