Information Quality, Disagreement and Political Polarisation

How does the quality of information received by voters affect political polarisation? We address this long-standing question using an election competition model in which voters have to infer an unknown state from some noisy and biased signals. Their policy preferences are shaped by the posterior belief, which is unknown to the parties when they choose their platforms. The greater the uncertainty faced by the parties, the greater the incentive to polarise. We show that better information can either promote or suppress polarisation, depending on the gap between voters' and politicians' beliefs (disagreement). We also examine the welfare implications of polarisation.