Given an overall rate of about 30-40% for single parenting,
I am going to walk this one back a bit. This data merely means that some portion of men are fathering children by more than one woman. While I know a fair number of single moms with children by more than one father, I can't demonstrate this statistically from the numbers here. So I retract that part. What is striking here is that, minus women left widowed and such, a fair number of women are in effect sharing the affections of their men with other women.
We could still infer, however, that with many women in effect "sharing" men, that those men would have difficulty making child support payments to multiple women, if they were even requested, and that as such it is no surprise that about half of single mothers report the fathers of their children are delinquent on child support payments.
I would also guess that they're more likely to receive welfare benefits, and fatherless children are also far more likely to commit crimes. At a cost of over a trillion dollars annually, maybe it's time to tell guys making child support payments to multiple women to learn what a bag of frozen peas is for.