Non-redundant groups, the assurance game and the origins of collective action

To discuss the origins of collective action this paper introduces the concept of the non-redundant group (n-group) of persons such that the contributions of all are needed, if outsiders do not contribute, to obtain the collective good. The paper shows that the members of an ''n-group'' face the structure of payoffs of the Assurance Game, and therefore, under certain conditions, will pursue collective action. The paper analyzes the situations where one or several ''n-groups'' exist and discusses the conditions under which an individual could know that he is an ''essential member'' of the relevant ''n-group''.