Economics Research Seminar Series: Mikhail Anufriev

Opinion formation is a complicated process that attracts the attention of economists, sociologists, psychologists, political and computer scientists. Studying opinion formation is even more important nowadays when the technological advances of the Internet and social networks allow people to get quick opinions on any issue from a very large and heterogeneous pool of sources. At the same time, the issues of the validity of information and its impact on information aggregation become important with the appearance of “fake news” and “internet trolls”. An unprovoked Russian invasion of Ukraine in February 2022 highlighted the influential role that state propaganda in Russia played and continues to play.

In his seminal paper, DeGroot (1974) proposed a model of social interaction in which dynamics of beliefs are given by an average-based repeated updating process. DeGroot learning is boundedly rational, because of the ‘correlation neglect’ phenomenon, the situation when the same information came to a person via multiple paths in the network. This learning model as well as the correlation neglect phenomenon has now received substantial support in the experimental literature.

The DeGroot model is based on the idea that people form their beliefs by taking into account the beliefs of others. However, since a belief is a state of mind, the model implicitly assumes that people express their beliefs honestly. In contrast, social psychologists emphasize a phenomenon of audience tuning by which individuals move their statements towards those of their peers to avoid the cost of cognitive dissonance (Higgins, 1999). For instance, relatives, friends, and colleagues would like to avoid unpleasant arguments over the dividing issues and thus may not express their views truthfully. Moreover, as people are driven by a desire to have a shared reality with others (Echterhoff et al 2009), their belief formation is affected by the saying-is-believing effect, when they tend to believe in their statements.

In a series of papers, we address and model these observations and study opinion formation with agents experiencing cognitive dissonance from disagreement with others. To minimize this dissonance, agents “tune their messages” in communication with their peers. Then they update beliefs based on statements of their influencers. For this model, we derive the limiting beliefs, the conditions for reaching a consensus in society, and the speed of convergence to the consensus belief. We then confront these conditions with the case of the standard DeGroot model with no message tuning. Our first result is that message tuning “cuts the distances” in social networks leading in some cases to the quicker propagation of ideas. Second, we show that the consensus beliefs in the connected societies are changing under message tuning giving a stronger impact to the less submissive agents. Generally, our results provide support to the earlier simulation study (Arifovic et al, 2015) not only for the case when the network is fixed, but also when agents minimize their cognitive dissonance by choosing the peers whose views are closer to their own.

As audience tuning leads to hypocrisy, we then look for the conditions under which agents may remain hypocritical over the whole dynamic process. We derive necessary and sufficient conditions for the absence and presence of hypocrisy and illustrate the consequence of hypocrisy for society via several examples. We show that our model can explain both the change of a social norm in favour of a minority group and the process of formation and reinforcement of the perceived majority belief. Our results can be interpreted as explaining the spiral of silence theory (Noelle-Neumann, 1974). According to this theory, the threat of isolation forces the perceived minority to stay silent about their true beliefs. Indeed, though the members of the perceived minority group keep their initial belief, under social pressure they make statements that are closer to the perceived majority belief. A sufficiently high level of social pressure felt by the perceived minority group leads the followers who are equally influenced by the perceived majority and minority groups to converge arbitrarily close to the perceived majority belief. As a self-fulfilling prophecy, the perceived majority belief indeed becomes the majority belief.