A reader from Wadsworth, Ohio, named Tom Morris writes with an idea. He is a lawyer and, he says, and an "occasional acting judge in a small town":
In my capacity as acting judge, I find myself repeatedly dealing with the same issues. Young adults irresponsibly having kids without any ability, either monetarily or emotionally, to raise them. These unwanted kids are left unsupervised, and are more likely to commit crimes and have more unwanted kids, which continues this cycle.
While I have not crunched the numbers to support this hypothesis, it is consistent with Dr. Levitt's study made famous from your first book. Unwanted children are a bad thing. Preventing this "bad thing" would lead to a reduction in crime, reduction in poverty, and a reduction of just about every other social ill I can think of.