This is an online-only extension of the conversation from the Spring 2008 issue of SSA Magazine.

Gun violence, which briefly overtook motor vehicle fatalities as the leading annual cause of death for people under the age of 39, was in decline between the late 1990s and 2003. Yet the United States still far outpaces other developed democracies in terms of guns as a cause of death-and homicides due to gun violence have started to rise again in many American cities. Gun violence also has a huge impact on distressed communities. This issue's "Conversation" covers the costs of gun violence, the options for limiting gun use, and how politics impacts policy.

SSA Professor Jens Ludwig is a faculty research fellow of the National Bureau of Economic Research, where he co-directs the working group on the economics of crime, and is also a non-resident senior fellow in economic studies at the Brookings Institution. He recently co-authored a paper in The Economic Journal, "Underground Gun Markets" that looks at how guns are bought, sold, and used in Chicago's poor neighborhoods. Roseanna Ander is the program officer in the gun violence program at the Joyce Foundation, which supports research and public policies to reduce the toll of firearm violence.

Ander: I think we've seen a new level of concern around the issue of youth gun violence. In the last year, the Chicago Tribune did a story about how many Chicago public school children had been killed just over the course of the school year. The number was somewhere around 34, and the vast majority-I think 28 or 30-were killed with firearms. And people are really starting to become galvanized around the issue.

Ludwig: It's interesting that those Trib articles have had such a large impact. When I ask people in the local philanthropic community, 'What do you think the most important part of the problem is?' they say youth violence, violence against school-age kids. And the city agencies that I talk to say the exact same thing.

I think it's worth noting that when you look at the Chicago Police Department crime data, almost no homicides occur in schools or on school grounds. With all of the policy interest in violence against school-aged kids-which I think is a very reasonable and defensible priority-it's easy to slip into the idea that there's a lot of school violence.

Ander Right. I think one of the dangers is the perception that schools are not a safe place for kids, when the research really bears out that schools are one of the safest places. And we want to encourage parents to send their kids to school. The tragedy is that it's in the home and walking to and from school or being in parks and other open spaces where the kids are at risk.

One thing that is important to talk about is the indirect costs of gun violence to society. One example: A survey has shown that a third of kids in urban settings have diagnosable PTSD, post-traumatic stress disorder, because of the high level of gun violence in those communities. You and Phil Cook, your mentor and colleague at times, did some terrific work trying to measure the other indirect costs of gun violence.

Ludwig: One of the most important things that comes out of our research is that the shooting victims aren't the only victims. Living with the fear that you or someone that you care about will be shot is an important part of the cost of gun violence, and that fear does things like drive city residents out to the suburbs. Julie Cullen [at the University of California, San Diego], and Steven Levitt at the University of Chicago have done a study about what crime does to urban flight. For every serious crime, one person leaves the city to move to the suburbs. For every homicide, 30 people leave the city to go to the suburbs. And one of the main things that guns do is they increase the chances that a serious crime turns into a homicide.

We estimate that the total cost of gun violence to the United States is probably on the order of about a hundred billion dollars a year. And again, a lot of that is borne by people who are not directly victims, but are still victims.

Ander: I was in Philadelphia last week, which has very high levels of gun violence. I talked to an executive there who's trying to recruit people, offering very high salaries. He said a salary of $500,000 a year is not enough to convince some people that they should live in a city where gun violence is such a problem.

Ludwig: I think that highlights a really important way of thinking about why we should care about reducing gun violence. There are moral and humane arguments. But if you're a mayor of a big city or you're a governor of a state, economic development is a very practical reason why you should care about this. It really is the case that your local property tax base, your local level of business activity depends in an important way on the city's ability to minimize the amount of gun violence.

Ander: Here's another example: I went to graduate school in Boston, where there was a pretty significant international body of students, many from developing countries. And their parents were more worried about them being in the United States in terms of safety than they were being back home in a country that may actually be going through some sort of a conflict or where there was a lot of unrest.

Ludwig: A lot of thinking is going on around the question of how to reduce gun violence in Chicago. Roseanna, I thought you could say a little bit about how the policymakers in the city are thinking about the youth violence problem and the crime problem in general.

Ander: There is a whole set of activities. The mayor has his legislative agenda to reduce gun violence. Every city agency has been tasked with making youth gun violence reduction a priority. So, for example, the police department's community policing efforts are very focused on how they work with young people.

We have a new police superintendent. The mayor continues to be committed to this issue. I'm curious about what advice you would give them to redouble or maybe focus their efforts.

Ludwig: There's evaluation evidence that suggests that targeted policing resources can bring down gun violence levels. The pioneering work of [George Herbert Jones Professor Emeritus] Irv Spergel here at SSA laid the groundwork for much of this research. The overwhelming majority of homicides in the City of Chicago are committed with guns and a very large share are committed in public places. An encouraging strategy is to focus police resources on neighborhoods where gun crime is at the highest levels and focus police activities on trying to stop and search for illegally carried guns. There's a fine line between encouraging police to stop people when there's probable cause and turning neighborhoods into police-state communities. But there are successful examples of police departments that have been able to walk that fine line.

Another tested intervention is focused activity against gangs. In the Boston Gun Project in the 1990s, police notified gangs that if any individual gang member was involved in a shooting, the whole gang would be in a vise, including activity to shut down their drug distribution activity. That changes the social norms within the gang away from encouraging reckless, dangerous behavior towards discouraging that activity, because it makes it harder for everyone to earn some money.

It sounds like the Chicago Police Department is essentially doing something very similar, even if it's not under any sort of formal programmatic name. Sudhir Venkatesh is a sociologist who got his Ph.D. from the University of Chicago several years ago. When he went out and talked to gang leaders in Chicago for our paper on gun markets, they told him that they know gun violence scares away customers and brings focused police attention that makes it harder to keep the drug distribution going. So Sudhir heard from the gang leaders that they regulate gun use, especially by the younger kids.

Ander: So if you're going to steal a car or you're going to be selling drugs, you don't want to have a gun on you, because that carries a double whammy. Unfortunately, the guns are still coming in. And so folks around the city are starting to organize and identify partners in other communities outside of the city to carry the message to the state capital in Springfield. This has to be a much more comprehensive statewide strategy.

Ludwig: That gets right at one of the most challenging aspects of the gun violence problem: Local government and even state government really have very limited ability to address this problem on their own through regulatory measures. Chicago has one of the most restrictive gun laws in the country, and the State of Illinois has an extremely restrictive set of gun laws. Yet the homicide rate in Chicago is still quite high.

The federal politics are so difficult, it's an incredible uphill battle to get even the most modest federal gun laws enacted. And usually what can get enacted at the federal level is extremely watered down to the point where any honest policy analyst wouldn't really expect it to do much good. Politically, states and localities have a lot better chance of enacting something more restrictive, but they're basically just little islands surrounded by oceans of easy gun availability.

Ander: I would agree. But state and local efforts can be a building block towards the political will for federal reform. And I think that they have the potential to have some impact. Research has shown, for example, that it would take the [U.S. Bureau of Alcohol, Tobacco, Firearms, and Explosives]-which is supposed to have oversight of federally licensed firearms dealers-years to inspect every dealer in the country, because they're so understaffed and under-resourced. And so state-level leverage over those licensees would give us some way to rein in gun dealers who are selling off the books and selling to straw purchasers, [when a convicted felon has someone not in a prohibited sales category buy the gun for him].

Ludwig: Many people have been convinced that a big part of the gun violence problem in Chicago comes from straw purchases from the suburbs. But in our study, when you actually look at the data on the guns that are confiscated in crimes, that really does not seem to be the case. It's a puzzle. You can open any Yellow Pages and find out where all the suburban gun dealers are. So Sudhir asked gang leaders, "Why don't you guys go to the suburbs to these gun dealers?" And what a lot of them say is that they just basically never leave their neighborhood. They spend most of their lives within a four or five block radius of where they live. And so the fact that there are not licensed gun dealers in that four- or five-block radius of their neighborhood in Chicago is potentially really important in limiting straw purchases.

I think it would be helpful if the mayors could form a group to generate political pressure to increase federal assistance for local and state police funding. I think the politics of the law enforcement side of reducing gun violence can be powerful. There's a reason that Bill Clinton talked about putting a hundred thousand more cops on the street. At its peak levels, the Cops Program was giving out something in the order of about a billion dollars a year in hiring grants to put additional police on the street. My understanding is the Cops Program didn't quite put a hundred thousand police on the street, but it put tens and tens of thousands of extra police on the street in the bigger cities in the country.

With the Bush administration, we've seen those hiring grants really atrophy. I think the past year from which I saw data, it was something like $5 million a year, a 99.5 percent funding cut. But the best evidence that I've seen suggests the Cops Program is unbelievably productive. The same issue, in principle, is on the table in 2008 for Democrats. They have the ability to run to the right of the Republicans on law enforcement.

Ander: I think that's right. One point that I'd want to make is this is actually a really solvable problem. I mean, we know a lot about what works and what would reduce gun death and injury. We don't lack answers or strategies; we lack political will.

Over the summer I read an article about an 11-year-old boy in England who was playing on a soccer field and was shot and killed in gang crossfire. The entire country was clamoring for action. One child, one 11-year-old child died, and that was intolerable and unacceptable. Now they're proposing additional restrictions on guns, other law enforcement strategies. Practically every day in cities across our country, we have 11-year-olds, five-year-olds, three-year-olds being killed. And we no longer feel a sense of outrage about it. We've just come to accept these deaths as normal.

But we have gun deaths increasing in a number of jurisdictions, and it's starting to get people's attention. I'm optimistic about passing new policies because we've done polling that shows that a majority of gun owners are very supportive of policies that we think would be beneficial. Where there's the disconnect is the leadership within the gun lobby. So I think we need to do a better job of reaching out to gun owners and making it clear that we need their voice to be brought to the debate.