A Comparative Analysis of Elite Affective Polarisation in Latin America: a Computational Linguistics Approach to Affective and Ideological Polarisation

While ideological polarisation is crucial in the functioning of democracies as it denotes competition between political parties and allows voters to distinguish between alternative options, affective polarization is commonly associated with distrust in political institutions and erosion of democratic norms. The interplay between ideological and affective polarisation in Latin America is unclear as politics largely revolve around leaders and group identities rather than established party systems. Understanding the dynamics that shape elite polarisation is relevant because elected politicians are typically perceived as a primary source of mass-level polarization. Building upon a rich dataset of tweets from Members of Parliament across nine Latin American countries between 2010 and 2023, we use state-of-the-art computational linguistics to measure ideological and affective polarization in parliamentary elites. The paper describes polarisation trends within and between countries. It explains variations in elite affective polarisation by examining the structural elements of the party system, the national contexts associated with the quality of democracy, and the attributes and behaviour of parties. Our data provides rich evidence on the extent and intensity of polarisation and, which complements existing measurements based on expert knowledge, population surveys, and evidence from policy positions and external documents. We show that the ideological distance between elites increases their levels of affective polarisation. At the same time, the high electoral volatility and democratic quality are related to lower levels of elite affective polarisation.