The Denial Odds Ratio can be used to gauge whether protected groups get a
negative outcome (like denial for a loan) more often than its control group. DOR
can be computed as follows:
Although there are no concrete fairness thresholds, industry practice2 has been:
2FairPlay considers a Denial Odds disparity exceeding 10% as practically significant. This aligns the Denial Odds Ratio and Adverse Impact Ratio metrics, which are two sides of the same fairness measure. If a protected group’s denial rate exceeds 110% of the control group’s rate, FairPlay flags a potential disparity. The fairness indicator for that group changes from green to yellow on FairPlay’s
dashboards, signifying a practically significant disparity that may merit corrective action. Additionally, to complement the Four-Fifths rule, FairPlay identifies Denial Odds ratios above 125% as practically significant disparities requiring internal attention. Since 0.8 is the multiplicative inverse of 1.25, a Denial Odds ratio of 1.25 (125%) or higher reasonably corresponds to an Adverse Impact Ratio of 0.8 (80%)
or lower.