Great Performance !

So it wasn’t capital punishment that drove crime down, nor was it the booming economy. But higher rates of imprisonment did have a lot to do with it. All those criminals didn’t march into jail by themselves, of course. Someone had to investigate the crime, catch the bad guy, and put together the case that would get him convicted. Which naturally leads to a related pair of crime-drop explanations:
Innovative policing strategies Increased number of police Let’s address the second one first. The number of police officers per capita in the United States rose about 14 percent during the 1990s. Does merely increasing the number of police, however, reduce crime? The answer would seem obvious—yes—but proving that answer isn’t so easy. That’s because when crime is rising, people clamor for protection, and invariably more money is found for cops. So if you just look at raw correlations between police and crime, you will find that when there are more police, there tends to be more crime.

That doesn’t mean, of course, that the police are causing the crime, just as it doesn’t mean, as some criminologists have argued, that crime will fall if criminals are released from prison. To show causality, we need a scenario in which more police are hired for reasons completely unrelated to rising crime. If, for instance, police were randomly sprinkled in some cities and not in others, we could look to see whether crime declines in the cities where the police happen to land.

Taken From : A Rogue Economist Explores the Hidden Side of Everything