False positives vs. false negatives: public opinion on the cost ratio in criminal justice risk assessment

Objectives We examine public attitudes towards false positives and false negatives in criminal justice risk assessment and how people’s choices differ in varying offenses and stages. Methods We use data from a factorial survey experiment conducted with a sample of 575 Americans. Respondents were randomly assigned to different conditions in the vignette for the criminal justice process and the offense severity and were asked to choose the cost ratio. Results While people prefer the cost ratio with higher false positives, the degree to which they accept false positives is lower than the cost ratios of existing risk assessments. The offense severity impacts people’s acceptance of false positives. Meanwhile, numeracy influences people’s decisions on the cost ratio. Conclusions To our knowledge, this is the first study to investigate public opinion on the cost ratio in risk assessments. We suggest that public opinion on the cost ratio can be an alternative way to find the ideal cost ratio.