Alternate policing strategies: Cost-effectiveness of cautioning for cannabis offences

There is increasing international interest in alternatives to the use of arrest for minor drug offences. While Australia has been at the forefront in the provision of diversionary programs for minor drug offences there remain key gaps in knowledge about the cost-effectiveness of different approaches. Here we set out to assess the cost-effectiveness of cannabis cautioning schemes whereby police refer minor cannabis use and possession offenders to education and/or treatment instead of arresting and charging them.

This study used a purpose built nation-wide online survey to evaluate cost-effectiveness of cannabis cautioning versus a traditional response for minor cannabis offences (arrest). The survey was completed by a self-selected group of detected cannabis offenders. The outcome measure was self-reported cannabis use days in the previous month post-intervention. Cost data included costs of policing, court, penalties, assessment, treatment and educational sessions. Propensity score weighting and doubly robust regression analyses were utilised to address differences between the groups.

There were 195 respondents who reported being arrested for a cannabis possession/use offence and 355 who reported receiving a formal cannabis caution. After matching on a range of characteristics (age, prior criminal conviction, cannabis consumption, employment status, self-reported criminal activity prior to detection, severity of dependence) there was no statistically significant difference in cannabis use pre- and post-police intervention between the two groups(N=544). After matching and bootstrapping the costs there was a significant difference in costs; the mean cost for the charge group (net of fines) was $733 (SD 151) and $388 (SD 111) for the caution group.

These results indicate that after matching on a range of relevant characteristics there were no differences across groups in the change in self-reported cannabis use days, but cannabis cautioning was less costly than charge/arrest. These results add to the evidence about the efficacy and desirability of alternatives to arrest both within Australia and abroad.