In this paper we develop a structural model of counterparty risk . In particular we provide closed form formulae for the price of risky debt and equity, which depend up on the lending/borrowing relationships in the economy. Our model applies to completely general lender/borrower relationships,...

This short paper establishes two conditions that allow to verify easily the strongquasi convexity of the objective function in a non linear least -squares problem, thereby the unicity of the minimum over a convex set.