Kristin Shapiro and Andrew Biggs have an innovative proposal, which they discuss in the WSJ:

What if the government could affordably provide paid parental leave to every worker in the U.S.? Our proposal is simple: Offer new parents the opportunity to collect early Social Security benefits for a period—say, 12 weeks—after the arrival of their child. To offset the cost, parents would agree to delay collecting Social Security retirement benefits, probably for only about six weeks.

Shapiro’s short paper on the subject, for the Independent Women’s Forum, is here. This approach seems to me superior to other ideas for expanding paid parental leave in that it 1) doesn’t make one-earner families subsidize two-earner families, 2) doesn’t give companies an incentive to avoid hiring women of child-bearing age, and 3) doesn’t raise federal spending overall.