David Yanagizawa, an economics job market candidate from Stockholm University, uses Rwanda’s hilly topography to look at the effect of the Mille Collines “hate radio” on violence.
Not all villages are in line of sight of the two national transmitters. The effect of being so? When a village has full rather than zero radio coverage, civilian violence increased by 65 percent and organized violence by 77 percent.[Link to the paper (pdf)]
NPR:
Gang violence is still a problem, but Los Angeles’ new police chief, Charlie Beck, says former gang members turned interventionists are helping put a dent in crime.
“Whenever a gang shooting occurs, we notify intervention, they do a couple things,” he says. “They, first of all, dispel rumors. Rumors cause the next homicide — rumors about who did what to who instigate further violence. So they calm rumors. They also create peace. They broker peace between feuding factions. They also mentor and try to remove gang members from the life of violence.”
Meanwhile, Blattman also draws our attention to this NYT Magazine article on group liability and gangs:
The police officer explained that while conventional deterrence hadn’t worked, he had begun to persuade gangs to behave by issuing a credible threat: namely, that when a gang attracted attention with notorious acts of violence, the entire gang — all of whose members likely had outstanding warrants or probation, parole or traffic violations — would be rounded up.