Australian Crime Trends and Population Ageing: A Quantified Perspective

Given that 15-24 year olds have a higher incidence of criminal involvement than other age groups, structural ageing can be expected to have a profound impact on crime trends. The purpose of this paper is to present preliminary findings from a research project that seeks to quantify the proportion of historical and projected change across the Australian criminal justice system attributable to changes in the population age structure. Major findings are that an age structure/crime pattern does exist, and operates in accordance with offender age profiles and the timing of the onset of demographic change. The proportion of persons in a population’s age structure aged 15-24 years can be expected to influence the respective population’s crime rate.1 Where the proportion of young persons in a population is large, the group’s impact on the respective crime rate will be large; if small, the impact will be smaller. Structural ageing – i.e. the increasing proportion of the population that is old- can be expected to influence crime trends as the 15-24 year age group undergoes a reduction in its population share.2 The Australian population is ageing structurally, and the age/crime pattern is similarly evident. It is probable that structural ageing is already influencing Australian crime trends and will continue to do so. Despite such anticipation, ‘one frequently overlooked influence on long-term crime trends is the age structure of the population ’ (Weatherburn 2001, p. 2). To date, the impact of structural ageing on Australian crime trends has received minimal attention, particularly in terms of systematic, quantitative research. This paper will consider the age structure/crime pattern in Australia on two levels: • firstly, the effect of structural ageing across offence categories and how these results can be interpreted in light of the age profile associated with various offences; an