Will more policing reduce crime?

It’s a fairly simple question, but simply put, will simply adding more cops to a city or neighborhood significantly reduce the crime rate there? What is the cost of adding more police compared with a certain drop in violent crime?

The obvious answer is, “of course,” but I’m curious to what extent this phenomena has been carefully observed.

I ask because I’m a recent transplant to the city of Philadelphia which suffers from a, shall we say, not insignificant number of murders and other violent crimes.

http://inquirer.philly.com/graphics/shootings_map_2007/

None the less, it seems like I can’t swing a dead cat in this city without hiting a police car or cop. In short, I’m not struck by any shortage of police.

So, to what extent will adding patrol officers or other police resources actually reduce violence in a city? Are there other areas where a significant body of evidence shows would be better places to spend that money to reduce violent crime?

If no one comes forward with a great answer, I’d suggest you skim:
http://www.socialsciences.uottawa.ca/ipc/eng/index.asp

Recalling college sociology classes:
Crime has tons of factors. There’s no single cause of a given crime or class of crime, and different crimes will require different solutions.
Philadelphia’s downtown neighborhoods may benefit from more of ‘type x’ crime prevention, while its suburbs need ‘type y’ crime prevention.
It could be that downtown needs less unsupervised public spaces while the suburbs need more places for kids to hang out after school and before their folks get home from work, while a neighborhood south of downtown but north of the suburbs proper just needs more jobs that pay a livable wage.

I am a firm follower of the “broken windows” theory.

More policing will not necessarily lead to less crime. Better policing most certainly will.

This issue was addressed in the now (in)famous Kansas City Study. The short answer is that police presence does not reduce crime and, in fact, leads to public dissatisfaction, disassociation, and a siege mentality.

A nutshell description of the method of the KCS is,

“Kansas City preventive patrol study- To see if the visible presence of police had an effect on criminal activity, the Kansas City Police Department conducted a study. In one area of the city, the department allowed no marked police vehicles except in response to a call; in another area, it performed an extra high level of marked, vehicular patrol; and in a third area, it performed regular preventive patrol. After a 12-month test, the study found no difference in criminal activity between the three areas. That result called into question the impact of a visible police presence on criminal activity.” (kycops.org/onlineCourse/guidebooks/Guidebook01.doc)

Also, see Wikipedia. (Kansas City preventive patrol experiment - Wikipedia)

The study IS dated (72/73) but is still widely cited when issues of police deployment are discussed.

Not in my observation - any more than more hospitals will make people healthier.

Police are only really effective after a crime has occurred.

Thank you.

Something like this is exactly what I was looking for. I guess the answer is not simply more cops.

More police won’t reduce crime, but more arrests will. People aren’t deterred by the severity of punishment, but by the certainty. That’s why red light cameras reduce side collisions, without getting into the whole subject of their increasing rear end collisions. Think of the “California stop”, the roll through a stop sign. The penalty for that is quite severe, hundreds of dollars in fines and points on your license and higher insurance rates, yet you see people do it every day. If the fine were to be $20, but every time you did it you got dinged, lots of people would stop doing it.

No more than you can inspect quality into a part. You need to address the root cause of crime, not the crime itself

I would expect that legalising drugs would reduce crime enormously.

Consider the ‘War on Drugs’. Billions of dollars have been spent with no discernable result.