тут посоны сообщают, что исследования по поводу резрешения оружия и его влияния на преступность сосут:

http://boingboing.net/2013/03/07/guns.html http://boingboing.net/2013/03/07/guns.html?

This process of taking the observational data we do have and then running it through a filter of assumptions plays out in the real world in the form of statistical modeling. When the NAS report says that nobody yet knows whether more guns lead to more crime, or less crime, what they mean is that the models and the assumptions built into those models are all still proving to be pretty weak.

“It’s been a complete waste of time, because we can’t validate one model versus another"