Still, the idea is rife with problems
- it's still going to impact women more than men (meaning ordering gender-equal leave will only mitigate the negative effects on the gender pay gap and female promotions, not eliminate them), because of single mothers and the like. Making the paid leave mandatory would actually hurt single mothers more than it being optional.
This impacts women's promotion prospects more than men. Sure, if a business makes a risk assessment on that basis, it's not gender-neutral. But is it sensible to ignore actual concrete differences? An insurance agency might charge men higher premiums because they're more at risk of heart disease. That's not gender-neutral either, but it's a realistic assessment of the costs and risk the company faces. Similarly, you can look at data about the typical age at which women have a child, and the proportion of women who do this, their marital status etc, and get a good estimate of the likelihood of a specific, known woman taking that break in e.g. the next 5 years. If the estimate is accurate, and you can estimate how much impact that will have on company profits if you promote that person to a mission-critical role, that's not being sexist, that called risk assessment as long as you use realistic variables and estimates.
- you'd have cases such as forcing executive mothers such as Sheryl Sandberg to take career breaks, especially if they were a single mom. This could affect the promotion prospects of single women, since they *could* have a baby and thus end up out of action, whereas a single man can't get pregnant.
- if only one parent works, and you mandate that that parent takes a break, then that is clearly going to negatively impact the entire family's finances long term. But if you try and mitigate that by saying "well if only one parent is working, the other one doesn't have to take leave", then you create a financial incentivize for some couples to plan it so that one parent quits their job when the baby comes, and that's going to skew towards the mother quitting her job more than the father.