Press Releases

1997 Releases

Study of Chicago Finds Neighborhood Efficacy Explains Reduction in Violence

For immediate release: August 14, 1997 

Boston, MA--In a major report from a large-scale study of human and community development, investigators show that lower rates of violence occur in urban neighborhoods characterized by collective efficacy. The study, published this week in Science, brings together data from the census, police and a citywide survey of more than 8,000 Chicago residents. It uses powerful new statistical methods to investigate why neighborhoods vary greatly in levels of criminal victimization and homicide. While many of the 343 neighborhoods studied are predominantly white, African-American or Latino, others are mixed in racial and ethnic composition. The investigators argue that collective efficacy, defined as mutual trust and a willingness to intervene in the supervision of children and the maintenance of public order, offers a deeper understanding of the social mechanisms that have linked neighborhood poverty and instability, in many previous studies, with high crime rates. An active and shared willingness to monitor children's play groups, help neighbors, and intervene in preventing acts such as juvenile truancy or street-corner loitering are key examples of neighborhood collective efficacy. The study, the Project on Human Development in Chicago Neighborhoods (PHDCN), is directed by Felton Earls, MD, Professor of Human Behavior and Development, Harvard School of Public Health. Working together with Earls are the paper's two lead authors, Robert Sampson, PhD, Professor of Sociology at the University of Chicago and Stephen Raudenbush, EdD, Professor of Education at Michigan State University.

Dr. Earls states, "We hypothesized that something other than race or poverty explains crime rates and that residential stability is an overlooked feature of relatively safer neighborhoods. We also thought that the extent of trust and reciprocity among neighborhood residents is influenced in part by social factors such as residential stability and a concentration of poverty. Therefore, we set out to better understand the contribution of these factors to interpersonal violence and the role collective efficacy plays in potentially overriding their impact. Indeed, although previous studies have cited a relationship between race, poverty and crime, our work shows that, after we control for social composition, collective efficacy is a strong predictor of the violence level in the neighborhood. In addition, residential stability is shown to have a strong positive influence on collective efficacy."

According to Dr. Robert Sampson, "Instead of external actions (for example, a police crackdown), we stress in this study the effectiveness of 'informal' mechanisms by which residents themselves achieve public order. In particular, we believe that collective expectations for intervening on behalf of neighborhood children is a crucial dimension of the public life of neighborhoods. Interestingly, some of the Chicago neighborhoods with the highest levels of this type of collective efficacy are African-American, middle-class and stable. By contrast, many of the areas low in efficacy and high in violence are unstable and heterogeneous--not necessarily the public housing projects that are disproportionately emphasized in popular discourse. In this sense our findings imply that achieving stable and safe neighborhoods is possible, although not necessarily easy, in all areas whether they be rich or poor, black or white."

Dr. Earls continues, "The importance of neighborhood efficacy goes even beyond violence reduction: these are areas that can extract resources and respond, for example, to cuts in public services, often circumventing the typical beginnings of neighborhood decline such as vacant housing or vandalism. It should be recognized that growth or maintenance of neighborhood efficacy depends upon the commitment of individuals but also external supports that enable trust and cooperation to flourish."

Analyzing data from survey respondents, the census and from police required statistical innovation. According to Dr. Stephen Raudenbush, "It was important that the analysis take into account the possible biases and the uncertainty that arise when a relatively small sample of persons in each neighborhood provides crucial information about that neighborhood. While to many people the findings may make sense, i.e., much has been reported previously about the value of community, this is the first time that the impact of one's neighborhood is measured on a large scale in a precise way. By providing this type of information, our hope is that decision-makers and local citizens will think in new ways concerning the means to prevent violent behavior in our young. These findings strongly encourage us to pursue the idea that neighborhood collective efficacy is a key factor in society's effort to control violence." The research team cautions, however, that problems such as poverty and residential instability cannot be neglected in any serious strategy to control crime and violence.

The PHDCN is a long-term study of the antecedents of violence which began in 1990. Another aspect of the study involves studying children and adolescents growing up in many of these same neighborhoods in order to understand the impact on their behavior of factors such as changes in family structure, social services and characteristics of the neighborhood. An on-going research effort to look at all the factors that could potentially contribute to behavior--the community, family, peers, as well as individual characteristics--PHDCN analysis is expected to inform the design of effective violence prevention strategies in communities and schools. Funding for this project comes from the John D. and Catherine T. MacArthur Foundation, National Institute of Justice, U.S. Department of Education, and National Institute of Mental Health.

For further information, please contact:

Robin Herman
Office of Communications
Harvard School of Public Health
677 Huntington Avenue
Boston, MA 02115
Phone: 617-432-4752
Email: rherman@hsph.harvard.edu