I am wondering whether the Canadian government has rules or policies for paying people equally regardless of the gender. If not, what is the reason for the difference in earnings?
Several Canadian provinces/territories have Pay Equity Acts.
I don't understand all the ins-and-outs of Canadian law, but in general it looks like these acts don't require that pay between individual men and women be equal. Instead, job roles can be categorized as "male dominated" or "female dominated". Female dominated job roles will have their pay adjusted to be similar to male dominated roles.