The Equal Pay Act requires that an employer pay its male and female
employees equal pay for equal work. The jobs need not be identical, but
they must be substantially equal. Substantial equality is measured
by job content, not job titles.
The Act is a strict liability law,
which means that intent does not matter. If a women is paid less than
male for substantially similar work, then the law has been violated,
regardless of the employer's intent.
This strict liability, however, does not mean that pay disparities
always equal liability. The EPA has several built-in defenses, including seniority, merit, quantity or quality of production, or any other factor other than sex.
A recently filed case out of Boston delves into these issues.