Corelab Seminar

Thodoris Lykouris (NTUA)
Competitive Contagion in Networks

We will present the paper "Competitive Contagion in Networks" by Sanjeev Goyal and Michael Kearns (STOC 2012). In their model, two firms with specified initial budgets "seed" the initial adoption of their products by consumers located in a social network. Those consumers later influence other consumers through a competitive stochastic diffusion process. The payoff of the firms is the number of players that adopt their product eventually. In this model, which is the first attempt to present competition under externalities in a non-trivial way, the inefficiency of resource use at equilibrium (Price of Anarchy) and the extent that imbalances in player budgets can be amplified under equilibrium (Budget Multiplier) are examined and the authors arrive at some interesting results.