The traditional service delivery concept is the economic market, in which the public service agency is the producer and the citizens are consumers. Based on feedback from citizens through voting, lobbying, or citizen boards, the public agency adjusts its policies. Because the agency is often bound by administrative rules, its individual agents fall back on their own personal experiences or prejudices. In contrast, in co-production the citizen as consumer assumes a much greater role, with citizen support and cooperation defining service patterns and also creates public services. Researchers vary somewhat in their definitions of co-production. Individual co-production includes residential security measures and crime prevention education; group co-production includes neighborhood watch programs; collective co-production includes witness assistance and auxiliary police programs. Although many barriers exist to co-production in law enforcement, support from the police chief for crime prevention through environmental design, putting a high-level administrator in charge of crime prevention, increasing the role of civilians in middle and upper management, and involving community leaders in a crime prevention committee are among ways to promote co-production and enhance crime prevention efforts.