There are certain ideas that are politically incorrect as well as too simple for it to be a respected opinion. A great example of an idea that is true and that people don’t like to think about is that one of the biggest reasons for crime's decline is more people in prison.
In his book why crime rates fell, Tufts University sociologist John Conklin concluded that up to half of the improvement was due to a single factor: more people in prison. The U.S. prison population grew by more than half a million during the 1990s and continued to grow, although more slowly, in the next decade. Go back half a century: as sentencing became more lenient in the 1960s and '70s, the crime rate started to rise. When lawmakers responded to the crime wave by building prisons and mandating tough sentences, the number of prisoners increased and the number of crimes fell.
Common sense, you might think. But this is not a popular conclusion among criminologists, according to Conklin. "There is a tendency, perhaps for ideological reasons, not to want to see the connection," he says. Incarceration is to crime what amputation is to gangrene--it can work, but a humane physician would rather find a way to prevent wounds and cure infections before the saw is necessary. Prison is expensive, demoralizing and deadening. "Increased sentencing in some communities has removed entire generations of young men" from some minority communities, says San Francisco police chief George Gascón. "Has that been a factor in lowering crime? I think it probably has. I think it also probably has had a detrimental effect on those communities."