On a Voter Model with Context-Dependent Opinion Adoption

Luca Becchetti (Sapienza University of Rome), Vincenzo Bonifaci (Roma Tre University), Emilio Cruciani (University of Salzburg), Francesco Pasquale (University of Rome "Tor Vergata")

Abstract

Opinion diffusion is a crucial phenomenon in social networks, often underlying the way in which a collective of agents develops a consensus on relevant decisions. The voter model is a well-known theoretical model to study opinion spreading in social networks and structured populations. Its simplest version assumes that an updating agent will adopt the opinion of a neighboring agent chosen at random. The model allows to study, for example, the probability that a certain opinion will fixate into a consensus opinion, as well as the expected time it takes for a consensus opinion to emerge. Standard voter models are oblivious to the opinions held by the agents involved in the opinion adoption process. We propose and study a context-dependent opinion spreading process on an arbitrary social graph, in which the probability that an agent abandons opinion 𝑎 in favor of opinion 𝑏 depends on both 𝑎 and 𝑏. We discuss the relation of the model with existing voter models and then proceed to derive theoretical results for both the fixation probability and the expected consensus time for two opinions on an 𝑛-clique network topology, for both the synchronous and the asynchronous update modes.