When we talk about the gender pay gap, we’re talking about a ratio: how much women make compared to men. We’ve spent the last three weeks talking about what happens to women’s earnings when they become moms. This week, we look at the other side of the ratio: Men—or more generally, secondary caregivers. When men become dads, their earnings get a boost, a phenomenon known as the fatherhood bonus. But if they try to do more at home than established gender norms say they should, they too are penalized. Susan Berfield tells the story of Kevin Knussman, a police officer whose career suffered when he tried to take time off to care for his wife and new baby. Then we talk to Alexis Ohanian, aka Mr. Serena Williams, about how we can actually get men to be more involved dads.