This dissertation consists of three chapters, each representing a self-contained research paper in health economics. The first chapter formalizes a model which generalizes several political models of collective action and regime change. It considers the impact that an extremist party can have on the choices made by the population in choosing whether or not to take part in a revolt. This third party is usually a personal interest group that benefits from a revolution, or in some cases benefits from the current regime in power, and thus will try to persuade the general population into pursuing an action that is in the extremist’s best interest. The paper presents several applications of the model with political and economic roots. These model...