How much safer can New York City get?

The statistics out of New York’s police headquarters for 2017 are nothing short of wonderful. This crazy polyglot metropolis of 8.5 million reported a total volume of homicides under 300, a rate per 100,000 citizens of 3.4, and a decline from the Gotham’s bad old days of 1990 of 89%. The city is bigger than ever, just as diverse and vastly less dangerous.

How did this happen? What happens next?

Two further details about public safety in New York deserve special mention before addressing the mystery of causes. First, it isn’t just homicide that has declined in unprecedented fashion; street crimes like robbery, burglary and auto theft have also dropped by close to 90%. Homicide numbers are worth special attention because it is the crime we most fear and the event that is the most difficult to hide from notice.

Second, the crime news remains rosy even when 2017’s totals are compared to non-crisis periods. By 2001, the city’s police force had already expanded by 40% and changes in police strategy had already produced the massive declines that made mayors and police chiefs into celebrities.

But the 649 homicides in 2001 produced a population rate of 8.1 per 100,000, more than twice as high as 2017, and 2001’s burglary and robbery rates also have dropped by half. Using homicide as a standard, New York is now the safest big city in the United States, with a homicide rate half that of Los Angeles.

So do we just applaud the NYPD? The effectiveness of New York policing is a major part of the city’s quarter-century of progress, but that doesn’t mean that the department should get the credit for every year-to-year improvement, just as it shouldn’t get blamed if the numbers turn negative. The almost 14% homicide drop from 2016 reported last year cannot be confidently linked to any of last year’s changes in policing.

And assuming that police patrols can micromanage citywide crime risks is not only bad science but is unfair to the police. Why not expect them to generate a homicide rate of zero?

It is of course reassuring that New York has the most successful municipal crime reduction achievement in modern history, but that distinction carries an important handicap. When the Los Angeles police chief is asked whether his city’s homicide rate can be reduced from its current rate of about 7 per 100,000, he can confidently say progress is possible because of New York City’s much more dramatic declines.

But New York City has no example of more successful crime reduction to point to as it tiptoes toward reducing street crimes to one-tenth of their historic highs.

Sure, there are cities in the world with homicide rates of 1 per 100,000, but not in a nation with at least 60 million handguns. New York is testing the limits of American possibility.

There are two important lessons that concern the capacity of effective policing to control crime. The first is the continuing preventive importance of street police. Whether or not the city’s homicide rates go up 6% next year or down another 12%, what a well-conceptualized and now better-behaved street police presence contributes to safe streets is substantial.

But New York is also a case study in the sturdiness of police effectiveness even when public and governmental criticism of cops becomes an important civic presence.

When crime rates turned up in many U.S. cities in 2015, right-wing pundits suggested that criticisms of police excessive force were undermining police morale and lessening police capacities to enforce the law and prevent crime. This theory was given an evocative label, “the Ferguson effect”; we were warned that the “war on cops” was producing a new crime wave.

If any city in the United States should be suffering from a Ferguson effect crime wave, it is New York City. The mayor who now enters his second term ran against established policing tactics when he got elected the first time. Police unions turned their backs on leadership at an official memorial service. A federal judge enjoined stop-and-frisk and the official rate of such stops has plummeted.

The ingredients for a blowback have been in place in New York City longer and more intensely than anywhere else. While there is much we don’t know about what caused the wonderful crime numbers of 2017, we can easily dismiss the crybaby criminology of the Ferguson effect.