"It is the demography, stupid"

The homicide rate in São Paulo dropped from 52 to 24 per 100.000 between 1999 and 2005. The usual explanations were quite unconvincing, but João Manoel Pinho De Mello and Alexandre Schneider have shown that changes in the demographic structure of the population can explain a large share of that drop. A must read if you are interested in violence in Brazil.