Estimating the impact of audio-visual link on being granted bail

By Min-Taec Kim

The aim of this study is to estimate the causal impact of appearing via audio-visual link (AVL) on the likelihood of being granted bail. Audio-visual link describes the video conferencing equipment to facilitate court appearances without the defendant being physically present. To estimate the impact of appearing via AVL on bail outcomes, we compare individuals who have their first court bail hearing via AVL at two NSW Correctional Centres, Amber Laurel and Surry Hills, between Jan 2018 and Feb 2020 with similar individuals over the same period. The credibility of the estimates hinge on two factors:
1) The extent to which we have observed and modelled the factors that influence the bail decision of the magistrate, and 2) The extent to which the allocation of AVL is ‘as good as random’ after controlling for all observed factors. Three statistical approaches (logistic regression, Mixed effects regression and a generalised random forest) are used to adjust for the observed differences between these two groups and estimate the causal impact of appearing via AVL.

Sydney: NSW Bureau of Crime Statistics and Research (BOCSAR), Crime and Justice Bulletin No. CJB235. 2021. 40p.