Criminal careers and the crime drop in Scotland

The number of recorded crimes has fallen in many countries, including Scotland, since the early 1990s. As crime is committed by people, this crime drop must be explained by either a reduction in the number of people offending (prevalence) or a reduction in the number of offences committed by people who do offend (frequency), or both.  However, to date, little work has been conducted on how patterns of offending have changed over the period of the crime drop.

This doctoral research, conducted by Ben Matthews, explores how the profile of people convicted in Scottish courts has changed over the course of the crime drop.  Using data on convictions, as a proxy for offending behaviour, it analysed change in patterns of conviction over time by age and sex, both of which have been shown to have a strong influence on the development of ‘criminal careers’.  As Scotland has experienced a similar crime drop to many other countries, this analysis has contributed to a better understanding of why crime has fallen and how criminal careers have changed over different periods of recent history. The analysis strongly suggests that policy changes in Scotland have had a specific impact on trends in conviction.

This research used data from the Scottish Offenders Index, a record of all people convicted in Scottish courts for offences committed between 1989 and 2011. It used statistical techniques (including standardization and decomposition, and latent class analysis) and methods of data visualization (lexis surfaces) to examine change in conviction patterns for men and women of different ages.

The results showed a sharp contrast between falling rates of conviction for young people, particularly young men, and increases in conviction rates for those between their mid-twenties and mid-forties. The result has been an increasingly even profile of convictions by age over time. However, conviction trends did not fall smoothly, and there were three distinct periods of change between 1989-2000, 2000-2007 and 2007-2011. The main factor driving these trends is a smaller proportion of young people being convicted (prevalence), rather than demographic change or change in the rate of conviction for those who are convicted (frequency).  Young people became less likely to be in the high-volume conviction groups estimated by the statistical model, while 25-40 year olds became more likely.  Higher conviction rates for those over the age of 21 were explained by more people continuing to be convicted at older ages and also more people receiving their first conviction after age 21.
This work indicates that patterns of offending did change dramatically over the period of the crime drop, especially for young people and young men in particular; however, an observed increase in convictions in the early 2000s was most plausibly the result of a punitive shift in justice policy at this time.

This research has, for the first time, brought together research on the crime drop with a developmental approach to studying criminal careers.  It has implications for both criminological fields.  Firstly, explanations for the crime drop in Scotland and elsewhere must be able to account for differing trends in conviction for men and women of different ages.  They must also take account of any difference in patterns of convictions during different periods.  Secondly, those who study developmental change in offending must take account of how changes in social context, such as the crime drop, influence patterns of offending and conviction.

Policy relevance:
This research is of relevance to policy makers and practitioners working with offenders, especially young people who offend, in Scotland and other jurisdictions.  The very distinct changes in conviction patterns indicate that older people are now more likely to be convicted of crimes and to remain in the criminal justice system for longer.  This has profound implications for criminal justice policy and penal interventions.  A better understanding of why convictions have reduced so much for young people might assist in the development of long term intervention strategies.  In addition, this work found that punitive justice strategies had a perverse effect on convictions.  It is recommended that similar work be carried out in other jurisdictions to determine whether such strong policy effects are apparent elsewhere

Further information:
Matthews, B. (2014)  Where have all the young offenders gone? AQMeN Research Briefing Number 4.

Matthews, B (2017)   Criminal careers and the crime drop: influencing Scotland's Youth Justice Strategy AQMeN impact case study 3

Matthews, B. and Minton, J. (under review) Rethinking one of criminology’s ‘brute facts’: The age-crime curve and the crime drop in Scotland.  Submitted to European Journal of Criminology.

See Ben discuss his work at AQMeN’s 2014 Festival of Social Science Event

A paper describing the change in the age-distribution of convictions and its implications for the study of criminal careers written with Dr. Jonathan Minton (AQMeN Research Fellow/University of Glasgow) is currently under review by the European Journal of Criminology.

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June, 2017

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