David Brooks called this statistic to our attention, and people are talking about it, but mainly in the context of objecting to Brooks's call for "a broad menu of" government programs. I want to question the blind leap from statistic to assumption that there is a problem.
The "prime working age" is defined as 25 to 54. If you heard that one fifth of women in that age group didn't work, would you assume that's a problem? Maybe you'd think it would be great if even more women choose to spend their time and effort on unpaid activities in the home and the community.
Tell me what these men are doing! Are they caring for children or aging parents, doing volunteer work, furthering their education, working on projects that may produce generate wealth next year? Brooks guesses that they are "idle." Are they? Can we get some fine-grained information about the individuals in that "missing fifth"? And how are they missing? The people who know them know where they are.
Let's not insult men just because they don't show up in the labor statistics. The government doesn't have them officially linked up with a tax-withheld-from-wages-paid job, but that doesn't mean they aren't functioning members of the community.