The objective of this paper is to explain the varying degrees of ideological congruence between a given political party and its constituency in the majority of Latin American countries. This congruence is considered as an important indicator of political representation in modern democracies and provides useful information regarding party-voters linkage. First, we discuss the concept of representation and the different approaches present in the literature, with emphasis on ideological congruence. In this sense, ideological orientation is considered as a heuristic category that reduces citizen information-gathering costs and facilitates voting decision making. Second, we propose and test a new measure of congruence based on the distribution of voters and party elites on the ideological scale. Third, several hypotheses are tested in order to explain the varying degrees of ideological congruence. We employ institutional and partisan factors as key explanatory variables. We propose four main hypotheses: the more proportional the electoral system, the more congruence should be found; the more democratic the process of candidate selection, the more congruent the linkage; the more coherent the ideological position of a party, the more congruence expected; the further left a party is positioned, the more congruence to be encountered. To achieve this objective we use data from the Latin American Public Opinion Project (Vanderbilt University) and Parliamentary Elites in Latin America Project (University of Salamanca). Due to data limitations, the scope of analysis is limited to the last two legislative periods for each country. Thus, we include parties with over 10 of representation in Lower Chambers, at the same time having at least thirty respondents for a party in the mass survey.
