An empirical study on micro influence and macro dynamics of opinion formation on the Internet

Social media platforms, comment boards, and online market places have created unprecedented potential for social influence and resulting opinion dynamics, which sparked a debate about the role of online media in the polarization of political opinions in many western countries. We propose an encompassing model that captures competing micro-level theories of social influence. Conducting an online lab-in-the-field experiment, we observe that individual opinions shift linearly towards the average of others' opinions. From this finding, we predict the macro-level opinion dynamics resulting from social influence. We test our predictions using data from another lab-in-the-field experiment and find that opinion polarization decreases in the presence of social influence. We corroborate these findings with large-scale field data.