This article makes vague reference to, but does not explicitly call out one major fact: Women have children.  Men do not, and our culture leads more women to choose to stay home with the children.

These choices increase the gap, and this isn't necessarily a bad thing.

Given the above, we could close the gap with one fell swoop - We legislate that all Canadian children must be in institutional care starting at 6 weeks old.  We will pay the workers in these institutions (Presumably the new mom's who aren't stuck at home anymore) $10,000 a month.

Voila.  Gap solved.  Never mind that we're ripping babes out of their mothers arms to do it, and closing the wage gap by paying a fortune for institutionalized care.

Families choose to have mothers at home with the children.  This is NOT A BAD THING.  One side effect is a wage gap.