Endogenous Changes in Public Opinion Dynamics

Opinion dynamics models usually center on explaining how macro-level regularities in public opinion (uniformity, polarization or clusterization) emerge as the e ect of local interactions of a population with an initial random distribution of opinions.However, with only a few exceptions, the understanding of patterns of public opinion change has generally been dismissed in this literature.To address this theoretical gap in our understanding of opinion dynamics, we built a multi-agent simulation model that could help to identify some mechanisms underlying changes in public opinion.Our goal was to build a model whose behavior could show di erent types of endogenously (not induced by the researcher) triggered transitions (rapid or slow, radical or so ).The paper formalizes a situation where agents embedded in di erent types of networks (random, small world and scale free networks) interact with their neighbors and express an opinion that is the result of di erent mechanisms: a coherence mechanism, in which agents try to stick to their previously expressed opinions; an assessment mechanism, in which agents consider available external information on the topic; and a social influence mechanism, in which agents tend to approach their neighbor's opinions.According to our findings, only scale-free networks show fluctuations in public opinion.Public opinion changes in this model appear as a di usion process of individual opinion shi s that is triggered by an opinion change of a highly connected agent.The frequency, rapidity and radicalness of the di usion, and hence of public opinion fluctuations, positively depends on how influential external information is in individual opinions and negatively depends on how homophilic social interactions are.