In The Richer Sex, Mundy starts with the fact that 37.7% of husbands right now earn less than their wives. Late in the book she allows that only 3.3% of husbands have no earnings, are home with minor children, and have wives with jobs. This book is not really about "breadwomen" - wives who are the sole or even predominant earners in their families. It is about two-earning couples in which, at least for a time, she earns more.
Mundy found, as others have before, that it is harder for wives to respect lower-earning husbands than it is for husbands to respect lower-earning wives. But Mundy also offers this helpful nuance: "If there's anything that every woman I interviewed can't stand, it's a partner who seems to be standing still." This makes sense to me. And this may be the main lesson to take from the book:
Wives outearning husbands is not a problem, any more than husbands outearning wives is. What both husbands and wives want is a partner who pulls his or her weight in the family, and who is ambitious to do it better.