De jure and de facto political institutions are quantified for a large number of countries since 1810. * The effects of de jure and de facto political institutions on long-run development are examined. * De facto institutions appear to be more important for long-run development than de jure institutions. * De jure and de facto political institutions explain up to 83% of development gaps across countries. This paper presents an attempt to quantify institutional changes and examine the respective effects of de jure and de facto political institutions on the path of long-run economic growth and development for a large panel of countries in the period 1810-2000. Using factor analysis, latent indices of de jure and de facto political institutions are constructed by exploiting several existing institutional datasets. The empirical evidence consistently suggests that societies with more extractive political institutions in Latin America, South Asia, Middle East and Eastern Europe have achieved systematically slower long-run economic growth and failed to catch-up with the West. The evidence confirms the primacy of de facto institutional differences over de jure institutions in causing differential growth and development outcomes over time. It also explains why highly concentrated political power and extractive political regimes inhibited the path of economic growth by setting persistent barriers to the engagement in collective action. In the long run, institutional differences account for up to two thirds of within-country development path and up to 83% of between-country development gaps.