Wednesday, August 27, 2025

Calculating "Win" Probabilities

A user-written Stata command available on SSC, [winprob], may interest legal scholars examining outcomes from two separate groups (e.g., treatment, control) in randomized controlled trials (RCTs). As the technical documentation explains, "winprob performs a non-parametric test for the win probability (also called the Wilcoxon-Mann-Whitney test probability, c-statistic, AUC, probabilistic index). The command returns the point estimate and associated confidence interval, standard error and hypothesis test for the win probability." In less technical language, "[winprob] calculates the non-parametric win probability of one group over another for a single outcome. The outcome can be ordinal or continuous. This is the probability of one group scores being at least as high or higher than those in the other group." More information, including on how to download, is found here.