Corrections Minister Mark Mitchell has claimed those serving longer sentences are less likely to reoffend and scrapping short sentences could make our communities safer.
However, there is robust disagreement with this interpretation of the data by experts.
The statistic that those on longer sentences in New Zealand are less likely to be reconvicted is an anomaly that bears exploring. I say an anomaly, because we don’t necessarily find the same outcome in comparable jurisdictions. There are a few suggestions that may begin to explain this finding.
The first is that we have a high proportion of people in prison for long sentences for sex offences. Sex offenders have a lower rate of reconviction than other offence types. The finding that people who serve longer sentences are less likely to be reconvicted in part simply reflects the reality that we have a high proportion of sex offenders in our prisons and that sex offenders are less likely to be reconvicted than other offenders.
Another contributing factor is that some of our rehabilitative, reintegrative, education and employment programmes reduce recidivism rates and that longer sentences supposedly give people more opportunity to complete these programmes. The decision by the National government to include remand prisoners in rehabilitative programmes is commendable.
However, legally allowing people to access programmes is not the same as ensuring adequate access to and resourcing of these programmes. Studies in New Zealand have shown that many people already struggle to access programmes for logistical reasons (inadequate staffing, inadequate resourcing, long waits, frequent transfers).
We are also still lagging behind other countries in providing the programmes most likely (based on empirical data) to reduce reoffending, such as access to higher education. We therefore could do a lot more to reduce recidivism, without extending sentences, if we made access to a wide range of programmes a key priority.
International findings demonstrate that prison overcrowding increases reoffending because overcrowding reduces access to programmes. Given that increasing sentences in New Zealand will dramatically increase our prison population, the obvious outcome would be that, without a commensurate increase in the availability of programmes, the resulting overcrowding would lead to more, not less, recidivism.
The Corrections Minister has indicated that longer sentences will work because people will "think about the consequences" and choose not to commit crime. This claim reflects a belief in marginal deterrence — that adjusting sentences lowers crime rates.
However, there is no evidence that this works and several reasons why this approach is ineffective.
First, most people are simply not aware of the maximum or average sentences for various crimes. It follows that tinkering with sentences is unlikely to change behaviour.
Second, much crime is what we call expressive crime: committed while experiencing anger, rage or depression and often while under the influence of drugs or alcohol. The people incarcerated in our prisons are significantly more likely than the general population to have experienced traumatic brain injuries, to have mental health challenges, substance use disorders, and to have experienced serious deprivation and violence themselves.
Changes in sentencing will not have an impact because these acts are not the result of a carefully considered cost-benefit analysis in the first place.
As to whether harsher punishments can deter specific offenders, the evidence does not bear this out either. And we know why.
Higher rates of unemployment, economic and social marginalisation, lack of pro-social relationships, and lack of future opportunities all increase rates of crime. These challenges are all worsened by prison. Statistically, we therefore see that sending people to prison increases their chance of reoffending.
Politicians should not trade optics around being "tough on crime" for the very real responsibility to make our country safer. There are evidence-based ways to reduce recidivism. In most comparable jurisdictions, prisoners can complete higher education degrees while incarcerated but this is not possible in New Zealand; and higher education is shown to significantly reduce recidivism.
The argument is often that not enough of our prisoners are eligible for higher education — yet jurisdictions like Queensland have more than 10 times as many prisoners enrolled in higher education as New Zealand has managed. Expanding and improving education and other reintegrative programmes is an evidence-based approach to reducing crime that does not require putting more people in prison for longer.
Jurisdictions such as Texas have successfully reduced their prison populations while simultaneously reducing crime. How did they do this? By focusing on a data-driven approach aimed at improving public safety, reducing corrections spending, and reinvesting savings into community-based programmes that are empirically shown to decrease crime and recidivism.
Would the exact same approach work here? It would probably need to be adjusted for the specific New Zealand context.
But we are unlikely to see safer communities and better outcomes unless we shift our perspective towards evidence-based, data-driven approaches.
And these can only develop in New Zealand if we are willing to work with experts, trial and carefully evaluate innovative programmes, and learn from successful approaches in other jurisdictions.
• Dr Fairleigh Gilmour is a senior lecturer in criminology and gender studies at the University of Otago.
