http://www.dailymail.co.uk/sciencetech/article-3710922/The-REAL-reason-modern-marriages-end-Women-likely-divorce-stay-home-dads-fail-live-breadwinner-stereotype.html

This isn't the first time I've heard this. Indeed, what we know based on other studies is that it's not just lack of income, but a man's income relative to his wife that matters most (for all income groups, poor, middle class, and rich). As a man's income falls relative to his wife his chances of divorce go up, with stay-at-home dads obviously in the worst possible position. A poor man with a stay at home wife is often in a better position than a man who makes less than his wife does at higher household income.

Source:

Despite a large literature investigating how spouses’ earnings and division of labor relate to their risk of divorce, findings remain mixed and conclusions elusive. Core unresolved questions are (1) whether marital stability is primarily associated with the economic gains to marriage or with the gendered lens through which spouses’ earnings and employment are interpreted and (2) whether the determinants of marital stability have changed over time. Using data from the 1968 to 2013 waves of the Panel Study of Income Dynamics, I consider how spouses’ division of labor, their overall financial resources, and a wife’s ability to support herself in the event of divorce are associated with the risk of divorce, and how these associations have changed between couples married before and after 1975. Financial considerations—wives’ economic independence and total household income—are not predictive of divorce in either cohort. Time use, however, is associated with divorce risk in both cohorts. For marriages formed after 1975, husbands’ lack of full-time employment is associated with higher risk of divorce, but neither wives’ full-time employment nor wives’ share of household labor is associated with divorce risk. Expectations of wives’ homemaking may have eroded, but the husband breadwinner norm persists.

http://jfi.sagepub.com/content/27/4/506.abstract