How Diadema, Brazil, Cut Murders in Half by Closing Bars Earlier

Diadema, an industrial city in the Greater São Paulo, in southeastern Brazil, with one of Brazil's highest homicide rates, has cut its murder rate in half in the last few years – mostly by establishing 11 p.m. as the closing time for bars and other places that sell alcohol. 

Researchers estimate more than 200 lives have been saved in the two years since bars went from staying open 24 hours a day to closing at 11 p.m.

The city averaged 22 homicides per month when bars were open 24 hours, but that rate declined to about 12 per month after bars began to close earlier.  The study findings are reported in the November issue of the American Journal of Public Health by researchers at the PIRE Prevention Research Center in Berkeley, California and at the University of São Paulo, Brazil and the University of Nottingham, England.

The researchers worked with government officials from Diadema to document the effects of the change. They examined the outcomes of limiting drinking hours in the city Diadema, which is about 12 miles from downtown São Paulo, the largest city in Brazil.

An industrial city with a population of 357,000, many of whom are low socio-economic status, Diadema had one of the highest homicide rates in Brazil, with 65% of such crimes considered alcohol related. 

Police statistics showed that most murders and other violent crime occurred between 11 p.m. and 6 a.m. near bars and retail alcohol outlets. In July 2002, a law was passed requiring that all alcohol establishments stop serving alcohol and close at 11 p.m. instead of staying open for 24 hours.

"Research has shown over and over that alcohol and violence are linked," said Dr. Joel Grube, Ph.D.., a study author and research scientist at PIRE. "The results of Diadema's efforts provide important evidence that this relationship need not be accepted passively.  Local communities have it within their power to prevent alcohol-related violence."

Researchers collected monthly police reports of homicides from local authorities to monitor the crime rate in Diadema. Leaders in Diadema worked both before and after the policy change to ensure that it had broad public support and was well-enforced. 

A public opinion poll before the policy change showed a community approval rate of 83%. Following the adoption of the municipal law, it was publicized throughout the community. Recent surveys indicate that 98% of Diadema residents know about the law, and 93% support the new alcohol policy. The mayor of Diadema was re-elected in 2004, with opinion polls suggesting increased popularity as a result of the new law.

"A wealth of research shows that policies that change how alcohol is sold can be highly effective in preventing alcohol-related problems.  This is another example of how those policies can work," Dr. Grube said.

Six months prior to the scheduled adoption of the new alcohol policy the municipal civil guard visited most alcohol retailers and discussed with the owners the proposed law and its application to alcohol sales.  Later, the owners were asked to sign a declaration that they were aware of the law and the legal consequences of violations.

Enforcement operations are carried out each evening.  An important component of the enforcement strategy includes regular meetings and reports to officers of the municipal civil guard on the effectiveness of enforcement in reducing community violence and informing officers directly of the survey data documenting citizen support for their enforcement efforts.

The analyses show that closing the bars at 11 p.m. produced a large and statistically significant reduction in homicides – almost nine murders a month in a city of 360,000 residents – an annual reduction of 106. This is a considerable public health achievement, especially in a country with such a high level of violent deaths. The data also suggest a possible reduction in assaults against women, although the effects were not statistically significant.

Between 1980 and 2004 the murder rate in Brazil more than doubled, from more than 11 to 27 per 100,000 per year. For comparison, the World Health Organization estimates that in 2000, the homicide rates per 100,000 people were one for the United Kingdom and six for the United States.