I’m answering your question, but not accepting the premise that childcare isn’t the major cause. Also, I’m coming at this from a Canadian perspective, where we

I’m answering your question, but not accepting the premise that childcare isn’t the major cause. Also, I’m coming at this from a Canadian perspective, where we have paid maternity/paternity via the Employment Insurance system. Despite it being available to both parents, anecdotally it is predominantly use by the mother, although fathers do sometimes use it (and it’s shared, so both can use it at the same time, eg when the child first come home). While the employer doesn’t pay for the employee while they are on leave, the employer is responsible for ensuring that their job is materially still there when they come back. Someone can’t go on mat/pat leave and come back to discover that they’re no longer a software manager but rather a janitor. In the meantime, you have to find someone to replace them. If you have two candidates, male and female, both are likely to have a number of risk factors: they’ll leave, they’ll seek raises, etc. But, to address your question, the woman also has some probability of having a child and taking mat leave. All other things equal (probability of other risks), the woman will likely have a higher overall risk, since she’s more likely to take mat leave. That all being said, you’re not “allowed” to discriminate based on that. And, as a man, I’ve never experienced sexual discrimination as far as salary goes. But there’s an answer to your question as to why childcare could be the primary factor.