In a continuous-time model of capital accumulation, there are convexity or concavity conditions on benefit and cost functions which ensure that dynamical necessary conditions for optimality are also sufficient. Non-convexities can occur in various ways: the Hamiltonian can fail to be concave...

This paper suggests a dual to the many-person applied welfare economics problem with constraints on lump-sum redistribution. The dual has the property of minimizing an aggregator function over individual income transfers. The properties of the aggregator are dependent upon the resource costs of...

This paper derives conditions under which prices may be set proportional to margin cost in some sectors of the economy when fixed distortions exist in other sectors. Two simple neo-classical economies are considered -- one with fixed producer prices and one with variable producer prices. In the...

This paper examines an industry where output is determined collusively, with output shares allocated on the basis of relative capacity. Capacity is chosen non-cooperatively, providing an apparently clear incentive for firms to install excess capacity. Although excess capacity equilibria (ECE)...