William Julius Wilson has been arguing for years that the low black marriage rate, and all the bad things that follow from it, is mostly because low-skilled, family supporting jobs disappeared from the northern cities at the just the time that African Americans migrated there in great numbers. Not having jobs that would support families, black men did not marry, and black women did not marry them. Wilson has never had a good explanation for why poor black women kept having children with men who could not support the children. Still, his structural account of why the black experience would be different from that of other immigrants has been a powerful answer to more cultural explanations.
In a more recent study, in Clayton, Mincy, and Blankenhorn's Black Fathers, Wilson extends his long-running studies of poor people in Chicago. Now he give comparative work and marriage rates not only for black and white men, but also Mexicans. This poses a problem for his basic argument about the black marriage rate. The Mexican immigrants are no better educated than the black natives in the poor parts of Chicago, and so have no better access to family-supporting jobs. Yet Mexican men are more likely to respond to their girlfriends' pregnancy by proposing and seeking some kind of job. Most poor black fathers, by contrast, do not pursue marriage. Indeed, Wilson reports that what all the poor mothers want from the fathers of their children is that they support the family and be faithful; the black men regard this desire as unreasonable.
When Wilson was comparing poor African Americans in the city today with poor Italians, Poles, Jews, etc. of yesteryear, his structural argument (work disappeared) could be persuasive. Now, though, when poor African Americans and poor Mexicans in the same city at the same time report quite different marriage rates, and therefore quite different male employment rates, his structural argument clearly has a cultural hole in it.