Kevin Drum attributes the recent fall in crime to anti-lead policies:
[M]y recollection of the evidence is that recessions have a mixed effect on crime rates. On the other hand, the cohort effects from lead abatement efforts and the introduction of unleaded gasoline probably continue to make themselves felt, so this might not be as mysterious as it seems.
Karl Smith goes further, writing that "crime and poverty in the first world are biological diseases." Drum ponders this and claims that "belief in biological determinism should make you into a liberal."
The Dish 