Before becoming mayor of Cali, Colombia, Rodrigo Guerrero was a Harvard-trained epidemiologist. Once in office, he led a data-driven fight against crime:
When Guerrero became mayor in 1992, the conventional wisdom was that the vast bulk of Cali’s murders stemmed from disputes over cocaine trafficking — at the time, the Cali Cartel was overtaking the Medellín Cartel in control of the cocaine trade.
But Guerrero didn’t assume, he measured. The police, courts and every other institution that counted murders all came up with different figures. Guerrero had weekly meetings with these groups and academic researchers to find more accurate figures. Then they mapped homicides by time and neighborhood.
That took about a year — and his term was only two and a half years — but he found something important: deaths were concentrated on weekends, especially payday weekends. (On his first New Year’s Eve as mayor, there were 22 homicides in one night.) The same was true in Medellín, which was why El Mundo’s crime reporters needed dozens of ways to describe violent death, as the Eskimo people are said to have for snow.
“Things that happen on the weekend in our country are often associated with alcohol,” Guerrero said. So Cali started to look at alcohol in the blood of victims (few perpetrators were caught) — and found a large percentage of victims had very high levels. “My initial hypothesis was that this was drug trafficking,” he said. “But the traffickers were not going to wait for weekends to resolve their conflicts — and get their victims drunk.”
The astronomical murder rate was related to the cocaine trade, Guerrero concluded — but only indirectly. Cocaine created social disruption and intensified an already-violent culture. “Drug trafficking was like H.I.V.,” Guerrero said. “It interferes with the defense mechanisms — in this case police and justice.” Those institutions were corrupted and degraded to the point where practically no one paid a penalty for murder — a suspect was identified in only 3 percent of homicides and convicted in a small percentage of those.
Guerrero banned the sale of alcohol after 1 a.m. on weeknights and 2 a.m. on Fridays and Saturdays. (That 2 a.m. is considered early closing says a lot about the problem.) As he expected, bar owners — and bar patrons — objected. Guerrero asked bars to try it for three months, but success was obvious nearly instantly. The effects were big enough to overcome the objections.
The other decree banned the carrying of guns — enforced by checkpoints and pat-downs — on payday weekends and holidays. The army, which held a monopoly on the manufacture and sale of guns, fought the law. But again, success was persuasive. Researchers compared gun ban days to similar days with no ban in Cali and in Bogotá, which replicated the program. They found that neighborhoods with the ban saw 14 percent fewer homicides in Cali and 13 percent fewer in Bogotá than neighborhoods without restrictions.
Together, those two decrees cut the homicide rate where they were instituted by 35 percent.
There was more: Since the data showed that a large majority of offenders were under 24, Guerrero instituted a curfew for young people in high crime neighborhoods between 11 p.m. and 5 a.m. on weekends.
As America’s ethnic composition becomes more like that of Colombia, this country will feel the need for more curfews, checkpoints, gun confiscation measures, and so on. It also seems likely that at some point we will desire a political strongman to implement these and other, perhaps harsher, measures.
Unfortunately, probably true. When the people who made democracy work are a minority, there’s no reason why a country should magically remain a democracy.