We study the canonical adverse selection contracting model using new techniques from generalised convex analysis. The fundamental duality in convex analysis between internal and external convexity extends from the classical affine case with linear valuations to the quasilinear case if and only...

This paper shows that market fragility and mass default can arise in microcredit markets as a result of the strategic interaction between a microlender using a reputation-based mechanism and a traditional lender using physical collateral. In our model, borrowers solve a dynamic programming...

Simultaneous exchange of valuable secrets is problematic without use of a trusted intermediary. Examples include trade between strangers involving the transfer of property rights at a distance by exchange of emails, and simultaneous signing of contracts. There is a danger that the first person...