Last week, the New York Civil Liberties Union released a report on police stops in New York City, prompting a New York Times editorial yesterday that was quite critical of the police. As the Times put it, “The mounting evidence reveals a pattern of abusive policing that warrants the attention of the Justice Department, which should be using its broad authority to investigate these practices.” The newspaper’s criticisms focused particularly on racial disparities in the NYPD’s stops and related uses of force.
Apparently by coincidence, the Milwaukee Police Department also released data last week on police stops, covering both subject stops (the topic of the NYCLU report) and traffic stops. The data indicate that the MPD and the NYPD have both significantly increased their numbers of stops in recent years. Although New York had far more subject stops than Milwaukee in 2011 in absolute terms, Milwaukee is actually in front of the Big Apple on a per capita basis.
Here are some of the key data (New York numbers come from the NYCLU report):
|
New York |
Milwaukee |
|
| Subject Stops (2011) |
685,724 |
60,294 |
| Population |
8,175,133 |
594,833 |
| Stops per 100,000 |
8,388 |
10,136 |
| Homicides |
515 |
85 |
| Stops per Homicide |
1,330 |
709 |
| Homicides per 100,000 |
6 |
14 |
| Stops (2007) |
472,096 |
14,063 |
| Change, 2007-2011 |
+45% |
+329% |
| Homicides (2007) |
496 |
105 |
| Change, 2007-2011 |
+4% |
-19% |
Thus, on a per capita basis, Milwaukee had nearly 21% more stops than New York in 2011. This represents a sea change since 2007, when Milwaukee’s per capita stop rate was less than half of New York’s. Although New York’s stops grew at a robust 45% clip between 2007 and 2011, Milwaukee’s stops truly exploded, with a 329% increase. (By way of comparison, New York had an almost identical 326% growth rate over the somewhat longer time period of 2003-2011.) Both cities have evidently embraced a dramatic change in policing strategy, although the change has been implemented in a more precipitous fashion in Milwaukee.
Is that a bad thing? It’s hard to assess the real impact of any policing strategy on crime rates because there are so many variables involved. It is interesting to note, though, that the homicide rate in Milwaukee has dropped markedly since 2007, while New York, with its slower rate of growth in stops, has seen an increase in homicides.
It stands to reason that an increase in stops will produce at least a short-term decrease in crime rates. A more aggressive stop strategy will disrupt crimes in progress and deter the planning of new crimes, as well as facilitate the seizure of guns and other contraband.
There are legitimate concerns, though, that high stop rates may prove counterproductive over the long run. Frequent stops in a neighborhood may undermine citizen trust in the police, particularly if stops are seen as racially discriminatory. This may undermine respect for law and legal institutions, and reduce the willingness of citizens to provide information and otherwise cooperate with the police.
There may also be adverse long-run effects to the extent that more stops lead to more arrests for drug possession, underage alcohol consumption, disorderly conduct, and other low-level offenses. Although an initial arrest of a young offender may produce helpful short-term deterrence effects, subsequent arrests likely have reduced marginal benefits, and a growing rap sheet clearly impairs the ability of the young offender to find satisfactory opportunities in the legal economy.
We might then imagine that continued year-by-year increases in the frequency of stops over a long period of time could produce a U-shaped curve in the crime rate: crime would initially go down, but the marginal benefits would level off; eventually, if stop rates continued to climb each year, crime rates might actually start to go up again. Perhaps we even see some evidence of this in the New York data. New York’s stop numbers increased significantly every year but one from 2002 to 2011. Accompanying the increase in stops, violent crime decreased every year from 2002 through 2009. However, violent crime has now rebounded with increases in both 2010 and 2011.
There may also be another sense in which ever-increasing stop rates may eventually prove counterproductive. A policing strategy that emphasizes the value of intrusions into the lives of citizens may promote a police culture that devalues the autonomy and privacy of citizens. This may, in turn, lead more police officers to become lawbreakers themselves. The line between lawful searches and seizures and criminal assaults and civil rights violations may be an uncertain one, but the line does exist, and police officers sometimes do cross it. There would be little reason for citizens to applaud a policing strategy that decreased their risks of being assaulted by a thug at the cost of increasing their risks of being assaulted by a cop.
None of this is to say that either New York or Milwaukee has necessarily reached the point of diminishing or negative marginal returns from increased stops — both cities might conceivably benefit if their police departments ratcheted up the number of stops even higher. The recent increases of violent crime in New York may be a statistical blip, or the result of factors entirely unrelated to the stop strategy. But the risks of adverse effects from high stop rates still merit attention.
Good training and supervision seem critical. It is important that citizens are not left with the feeling that a stop is an arbitrary exercise of police power. Psychologist Tom Tyler has done much influential research in this area, and his principles of procedural justice would seem a helpful starting point. He has, among other things, warned of the dangers of racial profiling.
The fact that complaints against the MPD have actually declined by more than 44% since 2007 suggests that in Milwaukee anyway there has been effective training and supervision as the number of police-citizen contacts has surged.
In a later post, I will take a closer look at racial and other aspects of the Milwaukee and New York data.
