Persuasion Bias, Social Influence, and Unidimensional Opinions

Abstract

We propose a boundedly rational model of opinion formation in which individuals are subject to persuasion bias ; that is, they fail to account for possible repetition in the information they receive. We show that persuasion bias implies the phenomenon of social influence , whereby one's influence on group opinions depends not only on accuracy, but also on how well-connected one is in the social network that determines communication. Persuasion bias also implies the phenomenon of unidimensional opinions ; that is, individuals' opinions over a multidimensional set of issues converge to a single “left-right” spectrum. We explore the implications of our model in several natural settings, including political science and marketing, and we obtain a number of novel empirical implications.