Interpretable Classification Models for Recidivism Prediction

We investigate a long-debated question, which is how to create predictive models of recidivism that are sufficiently accurate, transparent, and interpretable to use for decision-making. This question is complicated as these models are used to support different decisions, from sentencing, to determining release on probation, to allocating preventative social services. Each case might have an objective other than classification accuracy, such as a desired true positive rate (TPR) or false positive rate (FPR). Each (TPR, FPR) pair is a point on the receiver operator characteristic (ROC) curve. We use popular machine learning methods to create models along the full ROC curve on a wide range of recidivism prediction problems. We show that many methods (SVM, SGB, Ridge Regression) produce equally accurate models along the full ROC curve. However, methods that designed for interpretability (CART, C5.0) cannot be tuned to produce models that are accurate and/or interpretable. To handle this shortcoming, we use a recent method called Supersparse Linear Integer Models (SLIM) to produce accurate, transparent, and interpretable scoring systems along the full ROC curve. These scoring systems can be used for decision-making for many different use cases, since they are just as accurate as the most powerful black-box machine learning models for many applications, but completely transparent, and highly interpretable.