Network formation with systemic risk and default insurance

In this paper, we study the networks that arise in the equilibrium when risk averse investors play a network formation game for making joint investments with each other. The outcomes of these projects are stochastic and hence, depending on the shock realizations, investors may choose to default. However, counterparty defaults are damaging and investors have the option to buy default insurances against this damage. We show that in this model, equilibrium networks consist of complete components of a certain size, which maximize the expected utility of investors in that component. For a wide variety of parameters, it turns out that investors choose not to buy any insurance at the equilibrium.