Who knew that a union card was a turn-on?

Well, that might not be literally the case, but a new study finds that for men, union membership can boost their chances of getting hitched.

Research shows that for men, income correlates with marriage rates: The decline in marriage is more pronounced for men in middle and lower income groups. This basic relationship caused sociologists Daniel Schneider and Adam Reich to wonder: Would union membership—which is supposed to lift a person's wages—also lift a person's chance at being married?

Using 25 years of data from a cohort of men and women from the 1979 cohort of the National Longitudinal Survey of Youth, they found evidence that union membership is positively associated with marriage for men, though the relationship was not statistically significant for women in unions.

"We argue that membership in a labor union may increase the marriageability of young men and women either by helping to secure economic benefits in the present or by sending a signal to potential mates about the stability and certainty of future economic prospects," they write. "We find that men covered by collective bargaining have a significant advantage in first marriage and that this relationship remains after adjusting for possible confounding characteristics such as age, education, region, and attitudes."