More Police Does Not Lead to Less Crime

New research undertaken by the NSW Bureau of Crime Statistics and Research (BOCSAR) has added weight to the argument that increasing the number of police officers does not lead to a reduction in crime.

The study

BOCSAR researched the impact of extra police on rates of crime and arrests, by comparing the increase in the size of the NSW Police Force in the early 2000s to the rates of reported crime.

Between 2002 and 2003, the size of the state’s police force increased by 7.2%; which equates to around 10 additional officers per Local Area Command.

The fact there were few other variables at the time – and those variables were negligible – was important important to researchers, as they were of the view it enabled a credible analysis of the correspondence, if any, between increased police and reported crime.

To enhance accuracy, the researchers focused on offences known to be less susceptible to reporting and detection bias, namely murder, robbery, burglary, theft and car theft.

Some other offences, such as sexual assault and domestic violence, were not included as their reporting has been known to be influenced by attitudes in the community.

The findings

The study found that a 1% increase in the size of the police force did not affect crime rates, save for a 0.8% reduction in theft; a 1.1% reduction in car theft and a 0.63% reduction in aggregate property crime.

There was no reduction at all in violent crime rates.

Reason for decrease in property crime

For a given increase in police numbers, a change in arrest rate would either be a function of the deterrence rate or the incapacitation effect.

The difference is that, where deterrence takes place, people are choosing to commit less crime because they are scared of being caught. The incapacitation effect sees that people who would otherwise commit crimes cannot do so because they are already in prison.

In sum, the report did not find evidence that an increase in police numbers generates a significant change to the arrest rate.

This indicated that any change in crime that actually occurred, in regards to theft-related offences, were the result of slightly greater deterrence rather than incapacitation.

Cost versus benefit

The report also considered whether the wage cost of an additional officer is offset by the small benefit seen in property and theft offences. Ultimately, the report said that the costs of a slightly higher crime rate were more than the cost of an extra police salary, at least when using data from the early 2000s.

In this analysis, Mr Young used insurance claims data to find that the cost of a motor vehicle theft (in 2002) was about $6,000 per vehicle. Meanwhile, the cost of a NSW general duties constable (in 2005) was around $50,000 per year.

Using the findings above, this means that each additional police officer is able to offset almost half of their annual salary by deterring motor vehicle thefts alone. If other theft and property crime is added to this, it is likely that the savings in the cost of crime would offset the extra police salary.

This report does recognize that the findings for cost savings may not be generalizable to the present day. This is because there are modern innovations in security technology which mean that police play less of a role in preventing theft.

At the same time, these forms of theft and property crime would have fallen swiftly since the 2000s. Since this time, the rate of property crime has halved. Robbery without a weapon was down 64%. This means that the effect of police in deterring this would be weakened.

Bang for buck

It is also important to consider that this BOCSAR study did not consider whether the public funds of providing a police salary could better decrease crime through other means.

According to a 2012 BOCSAR report though, a more cost-effective strategy would be a committed investment towards alleviating, rather than just policing, underlying causes of criminal behaviour.

This report highlights the difference between reactive and proactive spending, stating “Measures that affect the economic well-being of the community provide more potential leverage over crime than measures that influence the risk of arrest.”

A 1% increase to income created a decrease in crime much greater than a 1% increase in arrest probability. Income effects were 14 times larger for property crime and about 5 times larger for violent crime.

The study of justice reinvestment finds that similar benefits are offered by investment into education, social welfare and family programs.

This data suggests that the salary of a police officer could be better used to decrease crime through spending efforts that target the true causes of crime; such as poor education, employment, mental health or family dysfunction.