Group Think: The opposite of traditional ''groupthink,'' our Group Think poses one question to a variety of smart thinkers for insightful perspectives on relevant issues.

What’s the Best Way to Fight Violent Crime?

The Connecticut school shooting sparked a national debate that focused mostly on two issues — gun control and mental illness. But in our inner cities, violent crime is way more common — and way more complicated. Many factors contribute to these statistics — poverty, segregation, gang warfare, drugs and policing strategies. In this Group Think, we asked experts to suggest factors that both contribute to and curb gun violence in American cities, using New York and Chicago as examples. In 2012, New York City’s homicide rate was the lowest since the city started keeping track in 1963. But in Chicago, homicide increased by 16 percent over 2011 — which was itself a bad year — and 2013 is already outpacing 2012.  We asked: What can we learn from New York’s success, and Chicago’s tragedy? What strategies for fighting violent crime work best — and at what cost?