This book reviews and explains introductory 'formal theory' in political science.

Part I. Basics: 1. The analysis of politics; 2. The models of Downs and Black: one policy dimension; 3. Two dimensions: elusive equilibrium; 4. Two dimensions: weighted Euclidean distance; 5. Social choice and other voting models; Part II. Extensions: 6. Uncertainty and policy preference; 7. The voting decision and collective action; Part III. Recent Advances: 8. Strategic voting, nonseparability, and probabilistic voting; 9. Mass elections; References; Glossary; Answers to exercises; Index.