More police on the beat means fewer problems on the streets

With the federal government unveiling a new community crime prevention program in the budget, and Labor emphasising community policing, it looks likely that crime may soon become a major federal issue. That well-known state candidate, Laura Norder, may soon appear on the federal ballot too.

While some see politicians talking about crime as a sure sign that good policy is headed for the slammer, a serious debate about tackling crime is long overdue in Australia. In the midst of an era of steady economic growth, an international survey of crime victimisation found that Australia had the highest rate of crime victimisation in the developed world.

According to a survey of 17 developed nations, we came top of the list for assault, burglary, personal theft and sexual assault. One in five people in other developed nations said that they had been the victim of a major crime in the previous year. The figure for Australia was nearly one in three.

Yet while crime in Australia is high and rising, the US has seen the opposite trend. During the past decade, crime in the US has plunged, with violent crime and property crime rates down by one-third during the 1990s. And according to a recent article by the University of Chicago's Steve Levitt, several oft-cited explanations were in fact pretty irrelevant to the reduction in crime.

So-called "zero-tolerance policing" tactics seem to have had minimal impact on crime rates. Strong economic growth might have had a small impact on property crime but is unlikely to account for any of the change in violent crime. And Levitt dismisses the notion that gun laws mattered much - either in the form of laws allowing citizens to carry concealed handguns, or gun buy-backs carried out by local jurisdictions (since criminals are pretty good at trading guns from one city to another).

So what does explain the fall in crime? The first factor that Levitt credits is the increase in police numbers. Using quasi-experimental evidence, Levitt finds that a 10 per cent rise in police numbers cuts crime by about 4 per cent. So thanks to several major state and federal initiatives during the past decade, more police on America's streets meant less crime.

Second, the growing prison population has had a major effect. With longer and stricter sentences, the US presently has more than 2 million of its citizens behind bars. This lowers crime both by incapacitating existing prisoners and by deterring would-be criminals from committing crimes. But while building more jails cuts crime, Levitt warns that incarceration has its own risks. Imprisoning a large fraction of young African-American men may keep crime down today, but at the cost of rising social problems tomorrow.

Third, a fall in drug-driven crime played a notable part in the overall crime drop. As any fan of Miami Vice or Beverly Hills Cop will know, the crack cocaine epidemic of the late-1980s was responsible for a large portion of the rise in inner-city violent crime in the US. But since the mid-'90s, stiffer penalties for crack use have deterred existing users and turf battles between drug gangs have become less common.

Lastly, Levitt argues that the legalisation of abortion in the early '70s helped reduce crime two decades later. This controversial theory rests on two premises - that unwanted children are more likely to grow up and commit crime, and that abortion reduced the number of unwanted births. Using variation in abortion rates across US states, Levitt concludes that nearly one-quarter of the total decline in crime during the past decade can be attributed to the legalisation of abortion. My own research (with Stanford University's Justin Wolfers) suggests that the same may be true for Australia.

So according to Levitt, America's crime success comes down to more police, more prisons, less crack and legalised abortion. On prisons and abortion, there is little for Australian policymakers to learn. Abortion is de-facto legal throughout the nation, and we are probably at the point where the social gain from increasing the jail population would be outweighed by the scarring effect of incarceration.

But on police and drugs, US criminologists may have something to teach us. Innovative policing, it seems, matters less than the pure number of police on the streets. And while crack-related crime was falling in the US, heroin and amphetamine-related crime was rising in Australia. Finding new ways to restrict the prevalence of hard drugs may help Australia bring crime down in the future.