At Statistics Canada we're very careful to try to present what we call the “stylized facts”, the statistical results. We do, of course, also do research on the gender wage gap, which tries to get at some of the more causal factors involved. It's notoriously difficult to get at the causal factors, basically because we simply don't know everything about the pathways women are taking to get to the point where they are earning, and earning less than men.
We do know, for example, that women are more likely to work part-time. We know they're more likely, when they do work part-time, to state that one of the reasons for working part-time is choice or family responsibilities.
There are ways that one can de-compose the gender wage gap into components like that. Certainly choice must play a role, but also, as I mentioned in my speaking points, there are norms in society, and the ways that women and girls are steered towards different occupations may also play a role.