Here are the major factors I've looked at: The previously mentioned (and most significant by far) years of experience (which for many women is affected by having children), hours spent at work, self-rated confidence, (personality trait) agreeableness, etc. etc.
The _entire_ point is that maternity, preconceived biases on women's behavior in the workplace, and expectations of women to do housework are factors that are to be contemplated and analyzed in their systemic causes.
There's a reason why in European countries parental leave is split between both parents and there's effort to make it easier for men to be caretakers.
If women are statistically likely to need to take more time off work than men due to being a parent, then I would argue this is effectively a systemic pay gap. Whether or not that needs fixing is another question but it's totally bizarre to say "if you ignore all the reasons why women are often in positions where they receive less pay that men don't have to deal with, there isn't a gap".
(To be clear: whether or not this pay gap needs addressing is its own question entirely. It makes total sense to me that a woman needs time off to recover from giving birth or from health complications during pregnancy.)
Here are the major factors I've looked at: The previously mentioned (and most significant by far) years of experience (which for many women is affected by having children), hours spent at work, self-rated confidence, (personality trait) agreeableness, etc. etc.