In this paper, we consider optimal reinsurance from an insurer's point of view. Given a (low) ruin probability target, insurers want to find the optimal risk transfer mechanism, i.e. either a proportional or a nonproportional reinsurance treaty. Since it is usually admitted that reinsurance...

We consider a model of socially interacting individuals that make a binary choice in a context of positive additive endogenous externalities. It encompasses as particular cases several models from the sociology and economics literature. We extend previous results to the case of a general...

We aim to identify the conditions under which social influence enables emergence of a shared opinion orientation among members of an organization over time, when membership is subject to continuous but partial turnover. We study an intra-organizational advice network that channels social...

An intricate web of claims and obligations ties together the balance sheets of a wide variety of financial institutions. Under the occurrence of default, these interbank claims generate externalities across institutions and possibly disseminate defaults and bankruptcy. Building on a simple model...

La faillite spectaculaire de la banque d'investissement Lehman Brothers a été perçue par de nombreux analystes comme un véritable point de retournement dans la crise financière actuelle. Le spectre du risque systémique a semé la panique parmi les investisseurs, non seulement aux...