This chapter re-interprets SEEN and DEEN models as non-cooperative Cournot-Nash games and constructs a cooperative bargaining game on the simplex of social welfare weights for SEEE and DEEE models. The basic models of environmental externality provision are now placed in the strategic setting. In the game-theoretic framework, the chapter studies the coalitional issues by defining and solving the hybrid Nash equilibria of the four basic models. We establish the superiority of the coalition formation based on the Lindahl principle. Again, the numerical example is provided to demonstrate the validity of the analytical results related to coalition analysis and programming codes are offered in the appendix. We also examine the relationship between the non-cooperative Cournot-Nash game and cooperative bargaining game in environmental externality provision issues.