SUMMARY This paper considers a class of one dimensional calculus of variations problems with monotonicity and comonotonicity constraints arising in economic and financial models where law invariant concave criteria (or law invariant convex measures of risk) are used. Existence solutions,...

We consider the problem of efficient insurance contracts when the cost structure includes a fixed cost per claim. We prove existence of efficient insurance contracts and that the indemnity function in such contracts is non-decreasing in the damage. We further show that either there is no...

In simple models of borrowing and lending with ex-post asymmetric information, Gale and Hellwig (1985) and Williamson (1986) have shown that optimal debt contracts are simple debt contracts where borrowers repay a fixed interest rate whenever possible and lenders seize all the profit when...