Employers defending against claims by persons aggrieved by what they believe to be unfair differentials in compensation may confront two theories of liability. The Equal Pay Act of 1963 (EPA), by its terms and title, requires equal pay for “equal work on jobs, the performance of which requires equal skill, effort and responsibilities, which are performed under similar working conditions,” subject to certain exceptions. Title VII of the Civil Rights Act of 1964 (Title VII) prohibits, less apparently, “discriminat[ion] against any individual with respect to his [or her] compensation … because of such individual’s … sex.” While the narrower goal of the EPA is reflected in the broader goals of Title VII, the proofs and defenses for each intersect and diverge by equal measure, demanding forethought and agility in litigation.

A plaintiff pursuing an EPA claim faces a prima facie burden of establishing: (1) the employer pays different wages to employees of the opposite sex; (2) the employees perform work on jobs requiring equal skill, effort, and responsibility; and (3) the jobs are performed under similar working conditions. If met, the burden of proof shifts to the employer to establish one of four statutory affirmative defenses—that the differential is justified by: (1) a seniority system; (2) a merit system; (3) a system that measures earnings by quantity or quality of production; or (4) a differential based on any factor other than sex that is supported by a legitimate business reason. Following such proof by the employer, the plaintiff must prove the factor put forward is pretext by demonstrating that the employer has not “used the factor reasonably in light of the employer’s stated purpose as well as its other practices.”