Long prison sentences can be just as effective as the death penalty in deterring homicides, according to new research from the University of Limerick.
Published in the Southern Economic Journal, the study reveals that life sentences, Standard Non-Parole Periods (SNPPs), where convicted murderers must serve a minimum of 20 years – have the same deterrent effect as capital punishment. The research suggests that countries can achieve public safety without the use of the death penalty.
Dr Vincent O’Sullivan, Associate Professor at UL’s Kemmy Business School, said the research is informative for policymakers considering the abolition of the death penalty, especially in the United States, where the death penalty is currently legal in 27 states. “Its usage had been declining since the 1990s, and several large states such as California and Pennsylvania are on the cusp of abolition.
“However, the Trump administration has indicated that it is very much in favour of the death penalty, so there will be much debate on this over the next few years”, he shared.
The study, co-authored with Dr Hugh Farrell, examined the history of the Australian legal system. Australia last used the death penalty in 1967. Research suggests the death penalty had a deterrent effect, reducing homicide rates by an estimated 7.6%.
However, he noted that the research confirms the deterrent effect of standard non-parole periods. “Some people might not want to remove discretion from judges and parole boards when it comes to sentencing. On the other hand, there is a public safety argument for lengthy and definite prison terms for the worst crimes in our society,” he said.
Dr O’Sullivan shared the importance of Australia as a case study for this research, he said it was due to the various sentencing laws in several states of Australia – compared to long delays of death row in the U.S.
Although the research focuses on deterrence, Dr O’Sullivan acknowledged the problems surrounding the death penalty.
“That is not to say that the death penalty should be re-introduced [where it is not currently legal]. There are many moral problems with such punishment, not least the problem of wrongful convictions.
“There is also controversy around the method of execution. In the US, pharmaceutical companies don’t want to supply drugs for lethal injection, so states are having to change their lethal injection protocols, or else use poisonous gas or even firing squads,” he concluded.
As discussions around criminal justice reform continue globally, the researchers hope their findings will provide evidence-based insights to inform policy decisions.
Dr. Vincent O’Sullivan is an Associate Professor of Economics at the University of Limerick. He is Course Director of the Bachelor of Business Studies. Before this, he lectured in Economics at Lancaster University from 2014 to 2021, focusing on health economics. Between 2010 and 2014, he worked as a research fellow with The Irish Longitudinal Study on Ageing. His research primarily explores how environmental factors, public policy, and individual behaviours impact the well-being of older adults. (Picture by Don Moloney)