Events

Professor Ashley Craig
Senior Lecturer in Economics
Research School of Economics
Australian National University

[Please note: our confidential data providers have disclosed our preliminary results for academic presentations, but not for public distribution. So although this abstract does not report quantitative results, the presentation will include them.] This paper estimates how changes in individual criminal behavior spread through social networks. To overcome identification challenges, we combine four existing randomized controlled trials (RCTs) in Chicago that all decreased violence (N=12,042) with multiple administrative measures of social networks prior to randomization (N>2 million). The resulting multiplex network captures co-arrest, co-victimization, shared classes, and shared households. We describe the network, estimate causal spillover effects, and study which social ties matter for criminal behavior. Both the direct effect of treatment and the full social impacts, net of spillovers, are considerably greater than those implied by the original intent-to-treat effects. The results improve our understanding of a set of influential experiments and clarify what the social nature of crime means for how we estimate the effectiveness of crime prevention.