Political corruption is a wide concept that involves all the branches of government and different political actors. Although, the incentives and opportunities to be corrupt vary among all these branches and actors, the literature about corruption has measured corruption mostly with
perception or surveys at the country level. These measures are a good approach to the general phenomenon, but they do not allow to test arguments based on specific branches or actors that could be affected by corruption. This article introduces a new index to measure the risk of
corruption in Latin American political parties, using information about the party system and internal party organization in each country. This new measure is an original approach to corruption inside political parties and has important implications. First, it allows researchers to test their hypotheses and state new arguments about the role of political parties and legislatures in reducing political corruption. Second, because the instrument measures the risk of corruption, it helps to understand how political parties could improve their internal organization to decrease
that risk. Finally, it is a useful instrument for cross-national studies in diverse fields that study political parties.