The Speed of Innovation Diffusion in Social Networks

Abstract:
New technologies typically gain an initial foothold through the actions of a few innovators, and then diffuse more rapidly as more and more people come into contact with prior adopters.
Much of the prior literature focuses on the rate of diffusion as a function of a fixed network structure in which the influence between neighboring agents is symmetric (the edges are undirected).
Here we derive universal lower bounds on the rate of diffusion that hold for directed and undirected networks of arbitrary size whose links may be evolving over time.