"I should start by saying that this is not a statement about abortion being right or wrong, about whether Roe vs. Wade is a good decision or should be repealed. It's a statement trying to understand the incredible decline in crime that we had in the 1990s. And I don't know how much people are aware of it, but violent crime is down almost 50 percent in the United States. And so I have spent about five years looking at all the usual types of suspects of why crime might have fallen. There still is a lot left over and I puzzled over this for years until one day I stumbled on to a set of statistics about the amount of abortion that takes place in the United States. It turns out after legalization in 1973 to the present, about one in four pregnancies in the United States ends in abortion. How can that not have a big social impact? And since I've been thinking about crime, I thought, `Well, is it possible this could really be linked to crime?' And it turns out there's decades' worth of social scientific research that suggests that if a child comes into the world, he's unwanted, has a difficult home life, that child's at tremendously increased risk for criminal activity. And so the theory is really pretty simple. After legalized abortion, there were fewer unwanted children being born. There are fewer unwanted children. When they grew up to reach their peak crime ages, they just weren't there to do the crime. And so it looks like about a third of this decline in crime that we saw in the '90s I believe can be attributed to the legalization of abortion."