“It isn't that I like my job more than my kids overall --if I had to pick, the kids would win every time. But the "marginal value" of time with my kids declines fast. In part, this is because kids are exhausting. The first hour with them is amazing, the second less good, and by hour four I'm ready for a glass of wine or, even better, some time with my research.

My job doesn't have this feature. Yes, the eighth hour is less fun than the seventh, but the highs are not as high and the lows are not as low. The physical and emotional challenges of work pale in comparison to the physical and emotional challenges of being an on-scene parent. The eighth hour at my job is better than the fifth hour with the kids on a typical day. And that is why I have a job. Because I like it.”