Why is an understanding of political competition essential for the study of public economics and public policy generally? How can political competition be described and understood, and how does it differ from its strictly economic counterpart? What are the implications of the fact that policy proposals in a democracy must always pass a political test? What are the strengths and weaknesses of electoral competition as a mechanism for the allocation of economic resources? Why are tax structures in democratic polities so complicated, and what implications follow from this for normative views about good policy choice? How can we measure the intensity of political competition, why and how does it vary in mature democracies, and what are the consequences? This Element considers the approach to answer these questions, while also illustrating some of the interesting theoretical and empirical work that has been done on them.