Males Lag Females in College Enrollment and Completion But No One Knows Why

Last year females received 58% of 4 year college degrees and males 42%. This gap has been growing for years , and also exists for initial college enrollment. The gaps for African American and Latino males are over 100% compared to females. I have examined numerous sources to try to understand the causes of this male/female disparity, but nothing has appeared yet that helps. There are all kinds of theories such as how k-12 female teachers interact with boys compared to girls, but no hard evidence.
Most of the commentary treats this issue as a discrimination and equity issue (eg the AAUW). But it is a major issue also for skill development in our economy, if such a large proportion of the labor force is undereducated. I wonder what the education gap is doing to the marriage market, but this is another arena for study.
The nation needs to focus on this male education gap and come up with some answers.