Introduction

Ever since the emergence of political theory, political thinkers have debated which political institutions foster democracies, individual freedoms, and good governance. Aristotle's analysis of different types of constitutional regimes and their political effects was retaken and elaborated on by most modern philosophers. Referring to the history of the Roman Republic as well as to contemporary evidence from Venice and other Italian cities, Machiavelli discussed at length the conditions underlying successful republican states in his Discourses on the First Ten Books of Titus Livy. In the Spirit of Laws, Montesquieu described in painstaking detail the foundations, structures, and operation of monarchies, aristocracies, and democracies and the potential causes of their decay. In turn, John Stuart Mill's Considerations on Representative Government examined the constitutional basis of a successful representative democracy.

Contemporary political scientists rekindled the debate on the potential effects of various constitutional structures in response to successive waves of democratic breakdowns across the world in the twentieth century. In an influential essay, Ferdinand Hermens argued that the fall of the Weimar Republic was partly caused by an extremely fragmented party system in turn fostered by proportional representation (Hermens 1942). Linz, among others, identified presidentialism as an important culprit in the instability and fall of several democratic regimes in Latin America (Linz 1994; Linz and Valenzuela 1994). More recently, the search for the “right” institutions to strengthen democracy has been bolstered by a growing formal literature stressing the equilibrium-inducing role of institutional rules and searching for “self-enforcing” constitutional norms.