Involuntary disputes. When competition for members forces smaller unions to strike

Industrial relations theory has produced two conflicting hypotheses on the effects of multi-unionism on the incidence of industrial conflict. International comparative research proposes that unions organizing the same worker domains are prone to competition, for which industrial conflict is used as a means of propaganda. British economic research claims that unions organizing substitutable workers cooperate and act as one union. This study argues that apparent cooperation is not always voluntary action but is sometimes the result of a loss of autonomy caused by competition and a lack of mobilization power. Micro-level data on industrial action are used to test hypotheses of the conditions for such involuntary participation in labor disputes.