The conventional wisdom is that Rudy Guiliani as mayor was responsible for turning around New York’s crime problem. Not so fast:
Giuliani took office in 1993, when the declining-crime trend was well underway. Crime rates were dropping rapidly when the much-maligned liberal David Dinkins was mayor, and had first started dropping when centrist Ed Koch (whose terms are off the left edge of the chart) was mayor.
New York’s turnaround from its low point in the 1970s has been a long process which has spanned the terms in office of three mayors. Giving all the credit for it to Giuliani is like giving all the credit for building a house to the drywall hangers and painters.
Moreover, a big part of the decline in NYC and elsewhere has been simple demographics and not public policy at all: Statistically, young men are the most likely to commit crimes, and the US population has been aging, causing that demographic to represent a shrinking fraction of the nation’s population.