http://www.dailykos.com/story/2015/10/23/1437781/-California-law-shows-how-wrong-Republican-opposition-to-paid-family-leave-is
"An analysis for the U.S. Labor Department led by Columbia Business School professor Ann Bartel last year examined dozens of studies on family leave. It concluded that while California’s policy prompted mothers and fathers to take more time, it didn’t harm workplace productivity, profitability, retention or morale."