In this article, we give an overview of the literature on the optimal forms of reinsurance as well as on results on how to fix retentions.

We start by giving an overview of the importance of reinsurance for the management of direct insurers and introduce most of the reinsurance concepts, namely, by presenting the different forms that reinsurance contracts can assume and how they affect the retained business of the insurers. We also explain how reinsurance can be placed and finish with some considerations about designing reinsurance programmes.