Social Networks and Diffusion: Avalanches and Links Evolution

Abstract:     
The concept of diffusion is central to every social system, because it underpins the coherence of individuals' behaviour and representations, and hence the coordination of their actions. The idea at the origin of the concept of diffusion is that inter-individual interactions are the driving force behind the evolution of individuals' behaviour, beliefs and representations. Our approach in this paper is based on social influence networks. Agents are embedded in social networks where the advance of influence depends on the propagation of "avalanches", giving central importance to the network structure. We consider the noise produced by those avalanches as a characteristic of the social structure that can contribute, through the evolution of links, to transforming the network structure, and hence the dynamics of the diffusion. We then explain why peculiar "critical" diffusion dynamics emerge, characterised by a power law distribution, instead of the exponential shape of traditional diffusion curves.

Keywords: Diffusion, social influence, social networks, structure, social learning, links evolution, power law

JEL Classifications: A13, D11, O30

Working Paper Series