But it also turns out that some countries that offer more liberal parental leave policies have higher pay gaps among men and women ages 30 to 34, according to analyses of 16 countries conducted by the Organization for Economic Cooperation and Development.
OECD theorizes that this link may be driven by the fact that women are more likely than men to actually use their parental leave, and that time out of the workforce is associated with lower wages.
It is rather obvious if you pay women not to work, they will accumulate less job experience and miss out on promotional and other career advancement opportunities in their prime of their career.
As this OECD paper in 2012 found with regard to paid parental leave and gender gaps in employment and earnings:
…the provision and gradual lengthening of paid leave have contributed to a widening in the gender pay gap of full-time employees.
This may reflect the fact that women experience slower career and earnings progression on returning from leave to full-time employment than men, much fewer of whom take leave.
In sum, the development of parental leave policies in most countries appears to have had a positive, albeit marginal, role in the rise of female employment, although women pay a price in the form of reduced earnings progression.
Claudia Golden found that in some high-powered professions, any career interruption at all, can greatly reduce lifetime earnings.
via The link between parental leave and the gender pay gap | Pew Research Center.