Eduardo Porter's column on the drop in college graduation rates in the United States relative to other wealthy countries ignored the large variance in the wages of male college grads. While there is little dispersion for the wages of women who graduate college, this is not the case for men.
There are a substantial number of male college graduates who can anticipate wages that are less then the top quartile of men without college degrees. The marginal college graduate is presumably more likely to be in this group of low earners. If they recognize the risk of not being a high earner many men may opt not to take the time and incur the expense of getting a college degree even if on average it would make them better off.