Gang members should stay in prison until they decide to stop offending or grow too old to be a threat.
You have to be a nasty piece of work to end up in prison for a long stretch in New Zealand. The Gluckman report found that too. He noted that 70 per cent of prisoners were inside for violence, sex offences or drug trafficking. I add that another 20 per cent are behind bars for burglary, fraud and theft. On average, you commit 11 offences before you are first sentenced to prison.
The notion that there are too many in prison is a most dubious idea. There are unsolved murders, rapes, armed robberies and burglaries. Many more criminals should be behind bars today but for lack of evidence or even simply not knowing who the offender was.
Much is made of the tougher bail laws adding to the prison muster. Everyone knows that the time on remand counts towards the final sentence. Unless found not guilty at trial, remand simply brings forward the same period criminals were to spend behind bars anyway.
Stronger bail laws only increase the prison population to the extent that more innocent people are remanded. About one in five prisoners on remand are not convicted at their trial and about the same number do not receive a custodial sentence.
To be found not guilty after being on remand is an error by the judicial system no doubt, but no system is perfect. As for those that do not receive a custodial sentence, their time served and any good behaviour while on remand will influence more judges to give a community-based sentence for the remainder of their punishment.
There is plenty of evidence that criminals are deterred by prison despite what many including the Gluckman report claim. The strongest evidence in the economics of crime and punishment is more police deter crime. The working rule is 10 per cent more police reduces crime by about 3 per cent.
As for longer sentences deterring crime, the clearest data comes from sudden increases in sentences unrelated to recent trends in traditional crime. For example, crime rates fell for the next six months after harsh sentences were handed down in the immediate aftermath of the London riots of 2011. Criminals decided not the chance their arm before the courts when longer stretches seemed afoot.
Good evidence that longer sentences deter comes oddly not just from fewer criminals ending up on in their third-strike in the US but more of those that do have committed a more violent offence. They still get the same 25 years to life anyway. They had nothing to lose in the over the top, indiscriminate severe punishment common in US three-strikes regimes. If they had something to lose, if their punishment was more tailored to their latest crime, they choose to be less violent.
Criminals are calculating in more ways than this. Burglary and theft rates respond strongly to rises and falls in the price of petrol, scrap metal and jewellery. Thieves also quickly respond to the spread of anti-theft devices to cars and mobile phones. Indeed, after the London riots, the only crimes that went up were offences other than riot type crimes such as robbery, assault, burglary and public disorder. Criminals plied their trade elsewhere in safer pastures. Arthur Daley would be proud.
Some say inequality and poverty are major drivers of crime. But they never mention the halving of murder rates in America since 1990 and the big fall in crime in general in the USA despite its reputation as the home of the greediest top 1 per cent and no universal health insurance.
While crime plummeted in the US, crimes apart from homicide grew in Europe. So much so that burglary and robbery rates are much higher in many Western European welfare states than in the mean old USA.
One-third of prisoners are gang members. Nearly all the recent increase in prison numbers are more gang members getting their comeuppance. Those wanting to reduce prison numbers are unlikely to campaign on the slogan "too many gang members are in prison". Over twice as many gang members are in prison than in 2010. This welcome development is driving the increase in prison numbers.
• Jim Rose is an economic consultant in Wellington.