Optimal debt contracts and the single-crossing condition

We argue that standard results proving that debt contracts can be obtained as the solution of an ex post adverse selection problem are derived without borrowers' preferences satisfying a proper single crossing condition. For a simple example where this condition is restored, we show that the optimal financial contract is not a standard debt contract, but rather an option contract. This casts some doubts on the robustness of existing results. (C) 1999 Elsevier Science S.A. All rights reserved.