This paper extends the work of Zhu Xianchen and Li Yulian (2007) by introducing the fairness compatibility constraint. Our work strengthens the explanatory power of their model. Whether a collective action can be realized depends not only on the organizer and followers’ individual rationality constraints, but also on their fairness compatibility constraints. Collective actions that meet the organizer’s individual rationality constraint but do not meet his fairness compatibility constraints cannot be realized. Furthermore, free-riders play a destructive role, which should not be ignored.