The impact of heroin dependence on long-term robbery trends
here for the full report (pdf, 154kb)
Release date: 10 December 2003
Recent research by the NSW Bureau of Crime Statistics and Research has shed some light on the growth in robbery that occurred in Australia between the mid 70s and 2000.
Between 1973/74 and 1988/89, the recorded robbery rate in Australia more than doubled. There are no national data on robbery between 1990 and 1992. Between 1993 and 2000, however, the recorded rate of robbery in Australia almost doubled again.
The increase in robbery has been particularly notable in NSW. Despite substantial falls in the incidence of robbery since the second half of 2001 (when the heroin shortage started), NSW still has the highest robbery rate in Australia.
Some observers have attributed the long-term upward trend in robbery to growth in the number of heroin users. Others have blamed the problem on falling clear-up and/or imprisonment rates. No one to date has thoroughly investigated the issue.
The Bureau examined the effect on the NSW robbery rate of four factors (a) the rate of unemployment, (b) the rate of heroin dependence, (c) the robbery clear-up rate and (d) the imprisonment rate for robbery (i.e. the ratio of convicted robbers imprisoned to total robberies).
Changing levels of unemployment do not appear to have had any significant long-term effect on rates of robbery in NSW.
The most potent influence appears to have been the upward trend in heroin addiction. The Bureau estimates that every 10 per cent increase in the number of heroin dependent people in NSW between 1966 and 2000, led, on average, to a 6.4 per cent rise in the rate of robbery.
Falling robbery clear-up and imprisonment rates also appear to have contributed to the long-term increase in robbery. However because these two factors are so closely related the Bureau was unable to separately estimate their effects.
All that can be said with certainty is that the effect of arrest and imprisonment is less substantial than the effect of heroin dependence. A ten per cent increase in the arrest or imprisonment rate, for example, leads to about a 3-4 per cent reduction in robbery.
The Bureau did not conduct any research into the reasons behind the fall in robbery clear-up and imprisonment rates.
According to the Director of the Bureau, Dr Don Weatherburn, however, the fall in robbery clear-up and imprisonment rates does not mean that police are catching fewer robbers or that the courts are imprisoning fewer of those convicted of robbery.
"It is important to remember that we were looking at the proportion of all robberies that led to the arrest and imprisonment of someone", he said.
"The number of arrests for robbery actually grew but it simply did not keep pace with the growth in robbery between the 1965 and 2000. Once the clear-up rate began to decline, the percentage of all robbers in prison at any one time inevitably began to fall with it".
According to Dr Weatherburn the research findings show that the best way to tackle robbery is through a mix of both treatment and law enforcement.
"The heroin shortage that took hold in Australia early in 2001 has led to a steep fall in the prevalence of robbery across the country and shown us how important it is to stem the flow of heroin across our borders".
"Encouraging heroin users into methadone maintenance treatment is also important because such treatment has been shown to be very effective in reducing their rates of involvement in crime".
"Ensuring a reasonable clear-up rate for robbery, on the other hand, helps deter and incapacitate offenders who are not dependent on drugs and/or who do not respond to treatment".
Dr Don Weatherburn (02) 9231 9190 (wk) / 0419 494 408 (mob)