A risk averse buyer and seller contract over the trade of an item. At the time of trading they each privately know their value s and cost r respectively, but these are not known when the contract is drawn up. The contract specifies a Bayesian revelation mechanism for implementing a trading rule and prices, as functions of their types s and r. An optimal (second-best) contract balances the goal of efficient trading and risk sharing against the need to provide the agents with incentives to reveal their type truthfully. An optimal contract is characterized. First, it is efficient to have some insurance from a third party: even though neither the buyer nor the seller will be fully insured, there is no need for the buyer to be exposed to the seller's risk or vice versa. Second, there will be less than first-best trade (underproduction). Third, once they have privately learnt their type—but before they have played the mechanism—both the buyer and the seller prefer that the final outcome will be trade rather than no trade. Fourth, although the trade prices increase with s and r, the rest of the contract need not be monotonic. This lack of monotonicity means that the standard methodology fails: it is not enough simply to appeal to local incentive compatibility, since global incentive constraints may bind. A nonstandard technique has to be used to find the nature of the second-best distortions.

This paper examines the use of stage mechanisms in implementation problems and provides a partial characterization of the set of subgam e perfect implementable choice rules. It is shown that, in many economic environments, virtually an y choice rule can be implemented. To illustrate the power of this approach, the paper discusses a number of models in which it is possible to implement the first-best (although it wouldn't have been possible to do so without using stage mechanisms). The diversity of these models suggests that subgame perfect implementation may find wide application. Copyright 1988 by The Econometric Society.

In this paper we present and estimate a model of economic depreciation consistent with producer's optimization. The estimated economic depreciation, which is a function of the rate of utilization and level of maintenance, is about half of that used according to tax (accounting) depreciation. The difference between the economic and tax rates of depreciation results in a subsidy and earlier capital replacement. The implicit maximum net tax subsidy expressed as a proportion of the acquisition price of the asset is 13.3% for a sample of Canadian trucking firms.

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In this paper we evaluate empirically the relative importance of two explanations of Yugoslav interindustry income differentials. One explanation, proposed initially by Vanek and Jovicic [1975], stresses capital market imperfections which permit capital rents to be appropriated as workers' incomes. The second explanation points to labor allocation problems under self-management. We first present a critique of the Vanek-Jovicic original formulation and then respecify the problem to permit simultaneous evaluation of the two schools of thought. Results based on two data sets suggest that labor allocation factors and monopoly power rather than capital rents are the main source of Yugoslav earnings dispersion.