Emergence of Equilibria from Individual Strategies in Online Content Diffusion

TL;DR

This paper models how individuals in social networks adopt new content based on threshold policies, using game theory and mean-field analysis to explain the emergence of these behaviors and their relation to content quality information.

Contribution

It introduces a game-theoretic mean-field model to explain the emergence of threshold policies in online content diffusion as a rational process.

Findings

Threshold equilibria emerge under specific parameter conditions.

Other equilibrium structures can arise depending on parameters.

The model links view counts to content quality inference.

Abstract

Social scientists have observed that human behavior in society can often be modeled as corresponding to a threshold type policy. A new behavior would propagate by a procedure in which an individual adopts the new behavior if the fraction of his neighbors or friends having adopted the new behavior exceeds some threshold. In this paper we study the question of whether the emergence of threshold policies may be modeled as a result of some rational process which would describe the behavior of non-cooperative rational members of some social network. We focus on situations in which individuals take the decision whether to access or not some content, based on the number of views that the content has. Our analysis aims at understanding not only the behavior of individuals, but also the way in which information about the quality of a given content can be deduced from view counts when only part of the viewers that access the content are informed about its quality. In this paper we present a game formulation for the behavior of individuals using a meanfield model: the number of individuals is approximated by a continuum of atomless players and for which the Wardrop equilibrium is the solution concept. We derive conditions on the problem's parameters that result indeed in the emergence of threshold equilibria policies. But we also identify some parameters in which other structures are obtained for the equilibrium behavior of individuals.