More recently, Baker and Milligan (2008) find that the introduction of the right to leave in Canadian provinces delays mothers’ return to work shortly after birth but increases the likelihood that they will return to their pre-birth employer. Similarly, Lalive and Zweimüller (2009) use the period before and after this time as a natural experiment to analyze the effects of these changes in entitlement on fertility and mothers’ labor market outcomes in Germany. Based on variation across births on either side of policy introduction, the authors show that extended leave delays return to work of mothers, even after the benefits are exhausted, resulting in significant reductions in female employment and earnings during the first three years after birth, but only minor effects beyond three years. Hanratty and Trzcinski (2009) examine the impact of the expansion of Canadian paid family leave and find no significant change in return-to-work levels by the 16th month after birth. Recent cross-country evidence from Europe (Del Boca, Pasqua and Pronzato 2009) explores the relationship between conditions in the labor market, a range of social policies (including parental leave) and women’s employment outcomes. The authors find that social policies have a large and significant impact on the probability of a woman being in employment, but that the relationship is much stronger for less-educated women for whom the relative costs of participation in the labor market are higher. They also find that while a legal entitlement to maternity leave has positive implications for women’s labor market outcomes, as it helps women to keep a formal connection to their employers, longer leave durations harm women’s career opportunities in the long term. Akgunduz and Plantenga (2013) present evidence of an inverse U-shaped relationship between maternity leave and women’s labor market outcomes. Using data from 16 European countries between 1970 to 2010, Akgunduz and Plantenga (ibid) find that parental leave is associated with increases in women’s labor market participation, particularly when participation is measured in terms of hours worked; however, longer durations of parental leave are associated with declines in wages for high-skilled women and with increased occupational segregation. Overall, Blau and Kahn (2013) show that “familyfriendly” policies, including parental leave, account for 29 percent of the decrease in US women's labor force participation relative to other OECD countries. The authors justify their results, arguing that parental leave may encourage women to stay out of the labor force longer than they otherwise would.

Using a differences-in-differences analysis, Schönberg and Ludsteck (2014) compare the labor market outcomes of mothers who gave birth shortly before and shortly after one of five major expansions in maternity leave coverage in Germany. The authors find that while expansions in maternity leave reduced mothers’ employment rates in the short run, the impacts were small in the long run. Dahl et al. (2016) obtain similar results, showing that the series of policy reforms implemented in Norway do not affect parental earnings and labor force participation in the short or long run. The conclusion that the effects of