Washington State’s Base Rate Study: A Practical Example of Research to Policy Partnership

• In Event: Research-Practice Partnerships as a Strategy to Improve Public Policymaking in State Justice Systems

Abstract

Risk assessment is now standard practice in corrections and the information produced by these tools informs practitioners at various stages of decision-making. Despite their widespread use, the output from these tools lacks standardization and consistency across assessments and jurisdictions. National efforts are underway to establish best practices in the development of risk assessment, including determining empirical recidivism rates that define the basis for each risk category (e.g., low, moderate, high risk). The purpose of our study was to determine the baseline prevalence of offending among the general population so that empirical base rates for correctional populations could be established from the bottom up. Using criminal history data and state population data, we examined the prevalence of criminal charges among the general population in Washington State from 2004 to 2016. The policy implications are clear: it is possible to determine the baseline prevalence of offending among the general population as the foundation for setting empirical risk categories for Washington’s statewide risk assessment. Establishing a base rate requires complex and thoughtful use of state data systems. This presentation describes the collaboration of SAJE partners to provide this needed source material for researchers, practitioners, and legislators.

Authors

• Andrew Peterson, Washington State Center for Court

• Elizabeth Drake, Washington State University

• Zachary Hamilton, Washington State University