What causes crime rates to go up or down?

Crime statistics show that both violent and property crimes dropped from 2008 to 2009, despite higher unemployment and a sinking economy. http://www.nytimes.com/2010/05/25/us/25crime.html?hp This is contrary to what many people believe. In the last year or so, friends and acquaintances would constantly ask me if my business was picking up due to the recession. The short answer is no..

Obviously with crime rates dropping, 'business' would be slower. But even more so, prosecution rates are dropping not only due to the dip in crime but also because state and local governments are cutting back on police, prosecutor and court budgets. My 'business' is far more dependent on prosecution rates than on crime rates. With the cuts in state and local budgets, another effect is felt: more lawyers without work. And when more lawyers are not employed by others, that means there are more of them competing to defend the shrinking pie of cases prosecuted..

But the bigger question is why are crime rates dropping in a recession? You'd think more unemployed people would mean more theft, robbery and other economic crimes plus more frustration, and perhaps more violent crime as well. Yet crime statistics from the 20th century show that the Prohibition era of the 1920's was far more violent than the Depression in the 30's. Experts do not have many well accepted theories on what causes crime rates to rise and fall. Some scholars have suggested such theories as: greater numbers of immigrants, who tend to keep a low profile; as opposed to this, others assert more illegal immigration increases crime rates; public housing policy dispersing the poor may decrease rates; legalized abortion (so fewer unwanted children are born) may decrease; the crack epidemic in the 1980's was thought to increase crime ; and changes in age distribution--e.g., the baby boom in the late 60's and 70's and the boomlet in the late 80's and 90's effect rates of crime..

The age distribution theory is probably the one most accepted. That is, crime rates tend to flow with the number of young males at a given time; the higher the proportion of young men in the population, the higher the crime rates since young men are by and large the biggest group of offenders. In fact, there is no strong statistical correlation between stricter law enforcement and longer sentences and the rise and fall of crime rates. See: http://www.psychologytoday.com/blog/the-scientific-fundamentalist/200808/when-crime-rates-go-down-recidivism-rates-go This just serves to show that politicians who emphasize 'law and order' as an issue may be just blowing smoke..

One interesting theory on why crimes rates might decline during a recession is it pulls families together, and this cohesion inhibits crime. More young people may move back home and are less influenced by their impulsive peers as well. There is also less economic activity in a recession so there is less interaction and opportunity for crime. Ironically, crime rates went up during the prosperity of the 1960's and one theory is that with rising wealth, the havenots and the people left out are more bitter and turn to crime. In contrast, when everyone's boat is sinking with the economic tide, there is more empathy, less jealousy and hence less crime. Of course none of this has been proven..

Finally, there are theories that smarter, better policing may reduce crime rates. For example, declining crime rates in New York City and Los Angeles are often ascribed to increases in the number of police on the streets, better computers for tracking crime, making precinct commanders accountable for managing crime in their districts, and an aggressive policy of searching people on the streets for guns. To be sure, the latter policy may deter crime, but makes it harder to obtain convictions if the Fourth Amendment is violated. Like many other factors, these claims of improved policing are unproven. Another possibility is that the increased use of very long 3 strikes sentences and federal mandatory sentences have cut back on the recdivist population. But that would not necessarily explain the drop from 2008-2009..

At this point, there is no final answer on what causes crime rates to go up or down..