Communication and the Emergence of a Unidimensional World

Abstract

Individuals hold and exchange opinions over multiple issues. However, a unidimensional spectrum is often enough to represent all those. As our theoretical and experimental results indicate, opinion differences can reduce to disagreement on a single dimension when individuals communicate and update their opinions in a boundedly rational manner, even when communication patterns are not (very) structured. Nevertheless, while communication is enough for the prevalence of unidimensionality, the presence of structured social networks proves crucial in predicting whether individuals form relatively moderate or extreme views and the importance of different issues on the shape of disagreement.

Keywords: opinion dynamics, information aggregation, persuasion bias, social networks

JEL Classification: D83, D85