There will be plenty of debate over the next couple of years about Mike Bloomberg’s tenure as Mayor of New York but just about everyone agrees that perhaps his biggest accomplishment was transforming most of New York City into a crime-free zone. Sure, there are still neighborhoods that aren’t safe, particularly some inner-city parts of Brooklyn and The Bronx. But if you live just about anywhere else in the five boroughs that comprise America’s most populous metropolis, the high levels of crime and violence that engulfed much of the city in the 1970’s and 1980’s seem to belong to a very distant past.

nypdOf course we also know that the drop in crime after the early 90’s wasn’t unique just to New York. Virtually every major metropolitan area registered steep declines in violent and property crimes beginning in the early 90’s and lasting for about ten years. Nationally, the violent crime rate dropped from 747 crimes per 100,000 in 1993 to to 386.9 in 2012, a decline of nearly 50%. Property crime went down over the same period about 40%, a remarkable change given the extent of the recession of 2007-2008.

In most parts of the country the decline of crime leveled around 2005 and has moved slightly upwards over the last several years. But remarkably enough, not only did the crime decline continue in New York but it actually became even more pronounced over the last several years. Frank Zimring, who studied New York crime through 2009, estimates that New York’s crime decline between 2000 and 2009 was at least twice as great as that of any other major American city, and in certain specific crime categories crime declined in New York over other cities to an even greater degree.

There are lots of theories out there that attempt to explain why the decline of crime in New York is both so steep and prolonged. Much of the credit usually goes to much more aggressive policing aided by computer-aided deployment of resources in high-crime zones. Tracking and curtailing the activity of street gangs and gun merchants also come in for examples of strategies that seem to work. But if you ask me, one of the real heroes in figuring out how to cut crime in New York should be the insurance agent who figured out that nifty idea to offer policy discounts for vehicles equipped with electronic burglar alarms, because if there’s one thing that’s driving (no pun intended) New York crime rates downhill, it’s the virtual disappearance from many neighborhoods of automobile theft.

Between 2000 and 2013, the category known as ‘grand larceny - auto’ dropped by more than 80%! No other crime category declined at that rate and no other crime category declined by at least 50% in every precinct in the town. The 5th precinct in lower Manhattan had just one reported vehicle theft per month, the 100th precinct in Far Rockaway, Queens, had less than two car thefts every 30 days. Even though car ownership in New York City is far below the national average, the DMV reports that there are still nearly 2 million vehicles registered in the city, and daily commuter traffic no doubt boosts this number by at least another half-million or more. With all that traffic there were less than 7,500 vehicle thefts reported for all of 2013. The police and Mike Bloomberg have done quite a job.

Actually the drop in auto thefts has little to do with effective policing because the truth is that with the new technologies it’s getting harder to steal a car every day. Of course a car thief may luck out and find a car door unlocked or a forgotten set of keys. But between incentives provided by insurance companies and aggressive enforcement of alternate-side parking which drives vehicle owners to keep cars off the streets, staying in business as a car thief isn’t an easy gig.

But if the cops and the Mayor don’t deserve so much credit for making it tough on car thieves, then this substantially changes the profile of crime in New York over the last twenty years. Because if we pull the auto theft numbers out of the overall crime data covering the last ten years, all of a sudden New York’s vaunted crime decline becomes somewhat less steep. In fact, the overall drop in crime since 2000 is no longer 50% but comes out around 20 percentage points less. This is still a very impressive number but it’s far below the level being thrown in Bill DeBlasio’s face today. I only hope that the new Mayor also knows how to read between the lines.