Seductions of Exposure Time: The Mismeasurement of Desistance among Persons Involved in Frequent and Serious Offending

Abstract

Examining desistance has become an important part of the longitudinal examination of patterns of offending. Substantial attention has been given to defining desistance (e.g., as a process versus as an event), but less attention has been given to whether analytic strategies appropriately operationalize such definitions. The current study examines the prevalence of false desistance (i.e., wrongly concluding that a person has desisted) when semi-parametric group-based modelling is used. Data on 404 male and female participants followed from ages 12 to 35 as part of the Incarcerated Serious and Violent Young Offender Study were used to jointly model trajectories of convictions and trajectories of incarceration. The conviction model included incarceration as an exposure variable. Nevertheless, approximately 15% of desisters in this conviction model were characterized by false desistance. That is, their lack of continued convictions appeared to be due to involvement in serious crimes that resulted in lengthy periods of time incarcerated. This precluded opportunities to maintain their earlier levels of offending, even though their conviction trajectories were modelled taking incarceration into account. Joint trajectory modelling should be used to improve the detection of desistance and reliably evaluate the predictive validity of constructs hypothesized to influence desistance.