TY - JOUR AU - Baker,Michael AU - Milligan,Kevin TI - How Does Job-Protected Maternity Leave Affect Mothers' Employment and Infant Health? JF - National Bureau of Economic Research Working Paper Series VL - No. 11135 PY - 2005 Y2 - February 2005 UR - http://www.nber.org/papers/w11135 L1 - http://www.nber.org/papers/w11135.pdf N1 - Author contact info: Michael Baker Department of Economics University of Toronto 150 St. George Street Toronto, ON M5S 3G7 CANADA Tel: 416/978-4138 Fax: 416/978-6713 E-Mail: baker@chass.utoronto.ca Kevin S. Milligan Department of Economics University of British Columbia #997-1873 East Mall Vancouver, BC V6T 1Z1 CANADA Tel: 604/822-6747 Fax: 604/822-5915 E-Mail: kevin.milligan@ubc.ca AB - Maternity leaves can affect mothers' and infants' welfare if they first affect the amount of time working women stay at home post birth. We provide new evidence of the labor supply effects of these leaves from an analysis of the introduction and expansion of job-protected maternity leave in Canada. The substantial variation in leave entitlements across mothers by time and space is likely exogenous to their unobserved characteristics. This is important because unobserved heterogeneity correlated with leave entitlement potentially biases many previous studies of this topic. We find that modest mandates of 17-18 weeks do not increase the time mothers spend at home. The physical demands of birth and private arrangements appear to render short mandates redundant. These mandates do, however, decrease the proportion of women quitting their jobs, increase leave taking, and increase the proportion returning to their pre-birth employers. In contrast, we find that expansions of job-protected leaves to lengths up to 70 weeks do increase the time spent at home (as well as leave-taking and job continuity). We also examine whether this increase in time at home affects infant health, finding no evidence of an effect on the incidence of low birth weight or infant mortality. ER -