Maybe. Many pundits have been talking about NYPD's use of COMSTAT, stop-and-frisk and fighting the "broken windows" syndrome as being leading causes of the drop

Maybe. Many pundits have been talking about NYPD's use of COMSTAT, stop-and-frisk and fighting the "broken windows" syndrome as being leading causes of the drop in crime in NYC. On closer inspection the crime appears to have been falling anyway for a number of possible reasons, some as simple as a change in demographics. Now we have perhaps something of a controlled experiment going on regarding the alleged root cause of the drop in crime in NYC (and perhaps nationwide).