Women now make, on average, 84 cents for every dollar a man makes, according to the Pew Research Center. This is an improvement from 64 cents per dollar in 1980, but on Equal Pay Day its worth exploring some factors that still hold women back from receiving equal pay to men.

It turns out the wage gap is even more narrow for one group of women: women ages 25 to 34 now make 93 cents for every dollar a man of the same age earns. But that gap widens for women over 35. And even more telling, unmarried women continue to make 94 cents to the dollar, while married women drop to 78 cents to the dollar. So why is this? Consider this excerpt from the Pew Research Center’s recent study on pay equality:

“In our survey, women were more likely to say they had taken career interruptions to care for their family. And research has shown that these types of interruptions can have an impact on long-term earnings. Roughly four-in-ten mothers say they have taken a significant amount of time off from work (39%) or reduced their work hours (42%) to care for a child or other family member. Roughly a quarter (27%) say they have quit work altogether to take care of these familial responsibilities. (Fewer men say the same. For example, just 24% of fathers say they have taken a significant amount of time off to care for a child or other family member.)”

In her recent book, Unfinished Business, Anne-Marie Slaughter singled out what she calls the “care penalty” as a main driver of gender inequality. Another scholar sees this as perhaps the largest factor in the remaining wage gap between men and women, stating that it is when women need flexibility to be caregivers that the wage gap begins, and continues for a lifetime.

Think about it. Men are able to continue on a career trajectory without any lost wages due to unpaid leave following the birth of a child, or lost promotions and raises due to taking leave, switching to part time, or cutting back on hours in order to care for family. At this point in a woman’s career, when she trades money and career for time with family, her career and thus earning potential is forever altered. Perhaps this is where the wage gap begins – and only widens as the years pass because most careers to not allow for a catch up.

So can paid leave, and equal leave for men and women, solve the wage gap problem? Some think so and there is some compelling evidence. For example, women who take paid leave, as opposed to unpaid leave, are 54 percent more likely to experience an increase in their wages a year after childbirth. In addition, when companies offer paternity leave, the “mommy tax” diminishes, because men take time off as well. In fact, one study by the Swedish Institute of Labor Market Policy Evaluation found that a mother’s future earnings increased 7% for every month that her partner took parental leave. This article outlines quite a few reasons why paternity leave might be the missing link to establishing equal pay.

Some companies are recognizing that paid leave and paternity leave allows women to remain equal in the workforce, even through child bearing and care giving years. List Your Leave shows which companies offer paid leave and which companies are supporting working families and gender equality. Add a review or policy today to show you support paid leave and equal pay.