Youth gangs have long been studied in the United States and interest elsewhere is increasing. Many studies document a robust and consistent relationship between gang membership and elevated delinquency. One theory of gang involvement, drawing on anomie and strain theories, proposes that the gang provides a means of fulfilling the economic needs of youth excluded from legitimate labour markets. Opportunities provision is a gang prevention strategy based on this theory and the principle that providing youth with educational and employment opportunities may reduce gang involvement. Common techniques within opportunities provision include tutoring, remedial education, job training, and job placement.