I'd assume the tax would be proportional to salary, sort of like social security. Some conservative napkin math: let's say that people have about a 30-year wor

I'd assume the tax would be proportional to salary, sort of like social security. Some conservative napkin math: let's say that people have about a 30-year working career and have on average 2 children. Let's say we want to give them 3 months off per child. That's 6 months of paid time off in a 30-year (360 month) working career or 1.66% of their career off. So taxes in that range would cover it. And actually people only need to get their after-tax salary in payments, which is smaller. And companies would probably be happy to pay into this because they no longer have the burden of paying the full PTO, it's amortized across the economy. Beyond taxes, the main contribution of the companies here would be that they need to hold the job for you while you're out and continue to provide non-salary benefits such as healthcare. My math is probably off but I think it's in the right ballpark!