Collective efficacy, defined as the normative property of social networks that pursue a common purpose, is a theory based on the work of Rob Sampson and Felton Earls. Efforts to promote collective efficacy try to close the gap between the generations, build social resources that promote reciprocal exchange between members of the community and encourage informal social controls - such as intervening to reduce anti-social behavior.
Evaluations of programs based on the theory have demonstrated promising results with respect to physical and mental health, inter-personal violence, child maltreatment, depression and risky sexual behavior. The CHASE program in Tanzania is a good example of the theory in practice.