Thesis (Ph.D.), Economics, Washington State UniversityThis dissertation analyzes firms' side problems in economics using an industrial organization approach to provide analysis and policy tools. In the first paper (Chapter 2), I analyze a setting in which firms appropriating the same common pool resource, such as fishing grounds or forests, have equity shares in one another's profits. I identify the firms' decisions of how much equity to acquire in equilibrium, the social planner's optimal equity shares and potential policy tools inducing firms to voluntarily choose socially optimal shares under this setting. In the second paper (Chapter 3), I extend the model of the first paper to a context of a Cournot duopoly. The key difference in thi...