PARLIAMENTARY FRAGMENTATION AND POLARISATION IN SPAIN: THE EVOLUTION IN THE CONGRESS OF DEPUTIES AND AUTONOMOUS REGIONS (1979-2022)

Abstract

Fragmentation and polarisation in Spain had so far been analysedwithtemporalorterritoriallimitations.Thispaper presents the levels of fragmentation and ideological polarisation in Spanish House of Representatives and in the Parliament of 17 autonomous regions from 1979 to 2022. The findings allow us to identify which chambers are more fragmented, where there has been more polarisation and how these two defining features of any party system have evolved over the legislatures. The levels of polarisation are calculated based on the parties’ ideological positions according to citizen perceptions collected by the Spanish Centre for Sociological Research (CIS). The results show the plurality within the Spanish parliamentary system, where the levels of fragmentation and polarisation vary according to various casuistries, in which the territorial dimension stands out as one of the most relevant. Moreover, there is a positive but weak correlation between the most fragmented and polarised parliaments.