Many books aren’t fact-checked, and we’re increasingly realizing they’re full of errors.

Kelsey Piper:

The problem? That finding is the result of a grievous misunderstanding on Dolan’s part of how the American Time Use Survey works. The people conducting the survey didn’t ask married people how happy they were, shoo their spouses out of the room, and then ask again. Dolan had misinterpreted one of the categories in the survey, “spouse absent,” which refers to married people whose partner is no longer living in their household, as meaning the spouse stepped out of the room.

Oops.

The error was caught by Gray Kimbrough, an economist at American University’s School of Public Affairs, who uses the survey data — and realized that Dolan must have gotten it wrong. “I’ve done a lot with time-use data,” Kimbrough told me. “It’s a phone survey.” The survey didn’t even ask if a respondent’s spouse was in the room.