Well not all of it, of course.  Most of it, along with the other anti-discrimination laws, are crucial to fighting intentional discrimination.  However, one particularly nagging part of the Equal Pay Act actually enshrines “unintentional” discrimination.  It is all in 29 USC Section 206(d)1, a sentence that starts out really well by banning discrimination, but then gives the following “out”:

…except where such payment is made pursuant to (i) a seniority system; (ii) a merit system; (iii) a system which measures earnings by quantity or quality of production; or (iv) a differential based on any other factor other than sex.

Here’s the problem, in statutory order:

1.  A (i) seniority system, by definition, pays people based solely on how long they have managed to stay employed.  Seniority systems are inherently discriminatory when any group of people will tend to have less seniority than others, e.g., when women take time out…