Quantitative Political Methodology

Ever since Aristotle, the comparative study of political regimes and their performance has relied on classifications and typologies. The study of democracy today has been influenced heavily by Arend Lijphart’s typology of consensus versus majoritarian democracy. Scholars have applied it to more than 100 countries and sought to demonstrate its impact on no less than 70 dependent variables. This paper summarizes our knowledge about the origins, functioning, and consequences of two basic types of democracy: those that concentrate power and those that share and divide power. In doing so, it will review the experience of established democracies and question the applicability of received wisdom to new democracies.

Logical models and statistical techniques have been used for measuring political and institutional variables, quantifying and explaining the relationships between them, testing theories, and evaluating institutional and policy alternatives. A number of cumulative and complementary findings refer to major institutional features of a political process of decision-making: from the size of the assembly to the territorial structure of the country, the electoral system, the number of parties in the assembly and in the government, the government’s duration, and the degree of policy instability. Mathematical equations based on sound theory are validated by empirical tests and can predict precise observations.

Rational choice theory may seem like a separate theoretical approach with its own forbidding mathematics. However, the central assumptions of rational choice theory are very similar to those in mainstream political behavior and even interpretive sociology. Indeed, many of the statistical methods used in empirical political behavior assume axiomatic models of voter choice. When we consider individual voting behavior, the contribution of rational choice has been to formalize what empirical political scientists do anyway, and provide some new tools. However, it is when we consider collective voting choice—what elections mean and what kind of policy outcomes result—that rational choice leads to new, counterintuitive insights. Rational choice also has a normative dimension. Without voter rationality the traditional understanding of democracy as popular choice makes little sense.