Marriage doesn't correlate to increased male earnings

Article here. Excerpt:

'Their analysis, however, is missing an important factor that might change the conclusions derived from these previous studies. They do not address the issue of whether self-selection could be a factor affecting the relationship between marriage and quality of life. In other words, it could be that happy and healthy individuals with more earning power are more likely to marry, painting a different picture of the effects of marriage. There is evidence to suggest that people select into marriage based on personal income, parents’ income, education, and whether or not are they are depressed. As such, research on the benefits of married life would not be complete without a discussion on selection mechanisms into marriage.

Already in 1987, two American researchers, Nakosteen and Zimmer, studied whether marriage affects the earnings of young men. They state that they "find no evidence to support that proposition." Based on a sample of 576 young men extracted from the 1977 wave of the Michigan Panel Survey of Income Dynamics, the authors show that marriage is not a direct contributor to earnings. Rather, the authors suggest that married men are selected into marriage by coming from a stronger economic background and that they are more attached to their jobs. 

Another study addressing the selection-causation question is a 17-year longitudinal study conducted in Germany. Using data from the German Socio-Economic Panel, the researchers investigated the marriage patterns of individuals in relation to their levels of happiness. The results suggest that happier singles are indeed more likely to get married, and that the benefits of marriage are more pronounced among happier individuals. Moreover, other psychological and medical studies suggest genetic selection into divorceand marriage.'