Building upon Iossa and Martimort (2008), we study the main incentive issues and the form of optimal contracts for Public Private Partnerships (PPPs) in transports. We present a basic model of procurement in a multitask environment in which a risk-averse firm chooses unobservable efforts in...

In this paper we explore theoretically the relationship between explicit and implicit/relational contracting distinguishing between the ex-ante decision to sign an explicit contract and the ex-post decision wheter to actually apply it. We show, among other things, that the relational efficient...