For all the mawkish, maudlin conservative hand-wringing about the state of marriage among the working class—recall Republican Mitt Romney, among others, recently claiming marriage as the solution to poverty—a post-mortem on marriage among the less materially fortunate turns up fascinating results. Poverty itself, it seems, is the chief agent of marital decline among the poor. This is especially true of falling wages among working class men, who have borne the brunt of the right-wing war on labor unions.

The trend was detectable even back in 2012, when Washington Post columnist Catherine Rampell pointed it out in the New York Times.

Forty years ago, about nine of 10 American men between the ages of 30 and 50 were married, and the most highly paid men were just slightly more likely to wed than those paid least. Since then, earnings for men in the top tenth of the income distribution have risen and their marriage rates have fallen slightly, from 95 percent in 1970 to 83 percent today. […] [M]en in the bottom quartile of earnings have had a wage cut of 60 percent, and a contemporaneous drop in marriage rates to about 50 percent, from 86 percent.

In a 2014 Atlantic essay, W. Bradford Wilcox of the pro-marriage think tank National Marriage Project also pointed to men’s dropping wages as the culprit behind declining marriage rates. “Working-class and poor women are less likely to see the men in their lives as marriageable or worth sticking with,” Wilcox reported. “Indeed, the research tells us that men’s income remains a strong predictor of marrying and steering clear of divorce court.”

In questioning marriage to men with precarious or despairingly poor economic futures, working class women are not displaying any kind of newfangled indifference to marriage, but rather old-fashioned prudence. Indeed, a study published by UCLA sociologists in the Journal of Marriage and Family found that poor people’s attitudes toward marriage and divorce are as—and often more—traditional than those of their upper-class peers. For a poor woman with low income, marrying a man with even worse financial prospects than herself is a liability to her and to any children she may have; moreover, the stress of a second source of financial insecurity is venomous to family formation.

But how do we explain the swiftly declining prospects of working class men? The Great Recession certainly appears to have disproportionately affected low-income male workers, but why? While the economic disparity can be partially explained by differences in industry participation between men and women in low paying work, there is yet another culprit, this one engineered by conservative politics: the decline of labor unions.