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OCB

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Organizational Citizenship Behavior is an individual behavior that is discretionary, not directly or explicitly recognized by the formal reward system, and that in the aggregate promotes the effective functioning of the organization.
Organ, D. W. (1988). Organizational citizenship behavior: The good soldier syndrome. Lexington, MA: Lexington

Organizational Citizenship Behaviors are contributions to the maintenance and enhancement of the social and psychological context that support task performance.
Organ, D. W. (1997). Organizational Citizenship Behavior: It’s Construct Clean-Up Time. Human Performance, 10(2), 85–97. doi:10.1207/s15327043hup1002_2

Organizational Citizenship Behaviors are discretionary contributions that go beyond the strict description and that do not lay claim to contractual recompense from the formal reward system.
Organ, D.W., Podsakoff, Ph.M. and MacKenzie, S.B. (2006) Organizational Citizenship Behavior: Its Nature, Antecedents and Consequences. Thousand Oaks, CA: Sage Publications.