53.3% of employed US mothers were on leave one month after having a child, versus only .8% for fathers [Han et al., 2009]. The 1993 Family and Medical Leave Act is exceptional in being a US policy mandating unpaid job-protected leave for specified family and medical reasons, including childbirth. Surprisingly little is known about the first-order labor market effects of this policy, principally for data reasons. Benefit mandates like the FMLA have costs and benefits which are notoriously difficult to assess.
