A Game-Theoretic Model of Misinformation Spread on Social Networks
31 Pages Posted: 26 Apr 2024
Abstract
We develop a game-theoretic model of sharing decisions among users of a social network. Agents are endowed with a subjective prior on an unobservable state, representing their beliefs on a topic that is subject to vote. Agents cast their binary vote, matching the sign of the state. Before the voting stage, a small fraction of agents receives a piece of news which impacts their belief. Those who receive the news update their belief and make a decision as to whether to share the news with their followers in order to influence their beliefs, and in turn their votes, given a fixed cost for sharing. We characterize the underlying news spread as an endogenous Susceptible-Infected (SI) epidemic process and derive agents' sharing decisions as well as the size of the sharing cascade at the equilibrium of the game showing that lower credibility news can result in a larger cascade than truth.
Keywords: Persuasion, strategic news sharing, spread of information, social networks
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