Disparate impact reaches practices that are neutral on their face but fall more harshly on a protected group, without requiring proof of intent.
Prima facie case. Identification of a specific employment practice and statistical evidence showing a significant adverse impact on a protected group. The plaintiff must generally isolate the practice, unless the elements of a decision process cannot be separated.
Statistical significance. Courts have used various measures, including a rule of thumb comparing selection rates and standard deviation analysis. Small sample sizes undermine both sides.
Business necessity. The employer must show the practice is job related for the position and consistent with business necessity — a demanding standard for selection criteria, requiring validation evidence rather than assertion.
Less discriminatory alternative. The plaintiff may still prevail by showing an alternative practice serving the employer’s interest that the employer refused to adopt.
Common subjects. Physical ability tests, cognitive tests, credit and criminal history screens, educational requirements, experience requirements, and now automated screening tools.
Self-analysis. Employers should run adverse impact analyses under privilege before adopting a selection procedure, and retain the validation evidence, which is the only defence at the business necessity step.