lunedì 11 gennaio 2016

Armi, omicidi e stati continua slatecodex

In yesterday’s post, I suggested that the difference in homicide rates between America and other First World countries were about two-thirds cultural, one-third gun-related. That’s sort of true, but people have reminded me to think of it as an interaction. Without the cultural factors in place, guns are pretty harmless.
Attenzione: Commenter Elias brings up this meta-analysis by Gary Kleck claiming that the 40 guns-and-states style studies he could find were split almost exactly half and half in terms of whether they found a significant guns-homicide correlation or not. He further claimed that the better the study, the less likely it was to find a significant correlation. The study I cited, plus my own analyses, passed two of Kleck’s tests – used good gun ownership numbers and controlled for confounders – but failed the third, which was distinguishing forward causation from reverse causation.