Games on Multi-Layer Networks

Walsh, A. M.

A set of agents is connected by two distinct networks, with each network describing access to a different local public good. Agents choose which networks to invest in, and neighbouring agents' investments in the same good are strategic substitutes, as are an agent's two investment choices. There are always equilibria where any investing agent bears all local investment costs and others free-ride. When investment in one good reduces marginal benefit from investment in the other, agents free-riding in one good may invest more profitably in the other, and equilibrium payoffs are more evenly distributed. This need not reduce aggregate payoff.