The authors of The Economic Effects of Constitutions use econometric tools to study what they call the "missing link" between constitutional systems and economic policy; the book is an uncompromisingly empirical sequel to their previous theoretical analysis of economic policy, Political Economics. Their findings are based on comparisons of political institutions across countries or time, in a large sample of contemporary democracies. They find that presidential/parliamentary and majoritarian/proportional dichotomies influence several economic variables: presidential regimes induce smaller public sectors, and proportional elections lead to greater and less targeted government spending and larger budget deficits. Moreover, the details of the electoral system (such as district magnitude and ballot structure) influence corruption and structural policies toward economic growth. Persson and Tabellini's study is important not only in its findings but also in establishing a methodology for empirical analysis in the field of comparative politics.