This is about more than fairness. It's about economic competitiveness. As American women have moved into the workforce over the past 40 years, they've driven a huge amount of growth — more than $3.5 trillion. But even as women have transformed our workforce, our workplace policies have not kept pace. Right now, women are breadwinners in two-thirds of families with children. That's why paid leave is so necessary. Without it, it's a lot harder to both work and have kids.