On September 15^th, Gallup’s monthly poll of adults in all 50 states and the District of Columbia went for the jugular: “What do you think is the most important problem facing this country today?”

Crime and violence finished 33^rd, tied with concerns about the media and “the way our children are raised.” In fact, less than one percent of Americans put crime in first place.  In the 1980s and 1990s, crime routinely headed the list.  Now Americans worry far more about inflation (which declined in June) and losing our military might (never mind that defense spending is at an all-time high, around $700 billion annually). The public sees crime as less of a problem today than some problems that aren’t even real.

Apparently, Americans believe we have defeated our crime problem.

Let that soak in for a moment. The nation’s list of conquered social ills is pretty short. We have vaccines that have markedly improved public health. We have much less lead in our blood since leaded gasoline was outlawed. Homicides by drunk drivers are way down. Medicare and Social Security mean few elderly Americans experience grave poverty and food insecurity. And that’s about it.

So are Americans right? And, if they are, what can we learn from our struggle to fight crime?

As for crime’s ranking, Americans are correct. It shouldn’t top the list. Crime has steadily declined since 1991--especially violent crime and especially in the past two years. Crime rates are down where they were when Richard Nixon was president.

So, the question is, what has led to improved public safety, and is it worth it?

Number one on the list is mass incarceration. According to the Pew Center on the States, 1 in 100 Americans was incarcerated in 2008 and 1 in 31 were in community custody or incarcerated. Among minorities, make that one in 9 black men between 20 and 34. Given the social and economic costs to families and neighborhoods, mass incarceration is an astonishingly expensive way to control crime. For example, a RAND study found domestic enforcement cost eight times as much to prevent as much crime as drug treatment.

Number two? On most lists, it’s policing. Many analysts say that improvements in police professionalism, police investigative practices and the introduction of proactive community policing have reduced crime.  This seems a likely explanation, but unfortunately we have too little data on crime and police practices to know how much better policing reduced crime, and we know it’s probably more expensive than alternatives to incarceration.

Number three is the end of the crack epidemic. Most drug policy experts think it died of natural causes as more and more of those in temptation’s way bore terrible witness to what happened to users. Here again, mass incarceration may have hastened its end, but again, at an exorbitant cost.

Number four is luck. Many explanations for crime's decline have nothing to do with public crime policy. The end of leaded gas is a prime example. Lead in the blood is associated with lower self-control—definitively linked to criminality—and lower IQ. But changes in the gasoline formula had nothing to do with crime fighting.

We have learned a lot in the last two decades of the crime decline about how public policy can prevent crime. “Best buys” are treatment for substance abuse, mental health and other disorders associated with criminality; educational and vocational training; and removal of stigmatizing laws. But these ‘softer’ alternatives to more marketable ‘tough on crime’ policies like prison are only slowly taking hold.

In some ways, it would be easier to fight crime and get better alternatives on the public’s radar screens if Americans worried about it more.  But for now, we are stuck with over-priced crime reduction.