So, I mentioned the problems with Levitt & Donahue's (2001) argument that abortion lowered crime.
Here is Ted Joyce, a professor at Baruch (and the CUNY Graduate Center) on the Leonard Lopate show out his argument for why the study is flawed.
Also the Wikipedia article on the topic has summaries of several different arguments for why the study is problematic.
Anyway, the most interesting thing about the original Freakonomics book was the chapter on the economics of selling crack. The basic conclusion was that everybody gets paid really badly including the higher ups who make around $100,000 a year. A decent living, but not great considering the risks taken on to earn them.
Anyway, I had a hard time with The Wire because I didn't believe that the heads of the gangs were rich enough to be big time real estate developers. However, here is another podcast that's an interview with a once big time drug dealer about the economics of selling drugs and he is very clear that he made a lot of money.