Democracy and the Logic of Political Survival

Although democracy is a key concept in political science, debate continues over definitions and mechanisms. Bueno de Mesquita, Smith, Siverson, & Morrow (2003) make the important claim that most of democracy's effects are in fact due to something conceptually simpler and empirically easier to measure than democracy: the size of the minimum winning coalition that selects the leader. The argument is intuitively appealing and supported by extensive data analysis. Unfortunately, the statistical technique they use induces omitted variable bias into their results. They argue that they need to control for democracy, but their estimation procedure is equivalent to omitting democracy from their analysis. When we reestimate their regressions controlling for democracy, most of their important findings do not survive.