Actually I forget where I read it but there is a hypothesis going around that the overall crime reduction has to do more with liberalization of things like birth control and access to abortion options.
At work at the moment and don't have time to pull up the details until tonight, but the examples given say of romania where none of the above is legally available still has a high crime rate. The general gist of things are that having to keep around kids a parent doesn't want tends to lead to bad outcomes for the children in life. Its much more complex than that and obviously we can't run randomized trials across multiple generations to validate things (not that it would even be ethical), but its interesting nonetheless.
The Freakonomics explanation (I just finished reading that chapter), says legalized abortion was a major contributor to decreasing crime rates in the 90's. However there were other contributing factors too. Author notes that it wasn't the "innovative policing strategies" of NYC that helped decrease crime rate, but the fact that they hired so many more police. There's a correlation there too. There's also a lot of discussion about crack cocaine and how that increased crime at its peak, but then related crime subsided.
At work at the moment and don't have time to pull up the details until tonight, but the examples given say of romania where none of the above is legally available still has a high crime rate. The general gist of things are that having to keep around kids a parent doesn't want tends to lead to bad outcomes for the children in life. Its much more complex than that and obviously we can't run randomized trials across multiple generations to validate things (not that it would even be ethical), but its interesting nonetheless.