This paper draws a remarkably simple bridge between auction theory and incentive theory. It considers the auctioning of an indivisible project among several fi rms. The firms have private information about their future cost at th e bidding stage, and the selected firm ex post invests in cost reduct ion. The authors show that (1) the optimal auction can be implemented by a dominant strategy auction that uses information about both the first bid and the second bid; (2) the winner faces a (linear) incenti ve contract; (3) the fixed transfer to the winner decreases with his announced expected cost and increases with the second lowest announce d expected cost; and (4) the share of cost overruns borne by the winn er decreases with the winner's announced expected cost.

The paper emphasizes the use of accounting data in regulatory or procurement contracts when the supplier (1) has superior information about the cost of the project and (2) invests in cost reduction. The main result states that, under risk neutrality, the supplier announces an expected cost and is given an incentive contract linear in cost overruns. This (optimal) contract moves toward a fixed-price contract as the announced cost decreases. An investment choice is then introduced and the use of a rate-of-return regulation is studied.

The paper emphasizes the use of accounting data in regulatory or procurement contracts when the supplier (1) has superior information about the cost of the project and (2) invests in cost reduction. The main result states that, under risk neutrality, the supplier announces an expected cost and is given an incentive contract linear in cost overruns. This (optimal) contract moves toward a fixed-price contract as the announced cost decreases. An investment choice is then introduced and the use of a rate-of-return regulation is studied.

We study the behavior of a large trader with private information about the mean of an asset with a risky return. We argue that if the variability of the return is not too great, typically the trader will find it desirable to ensure that the market price does not reveal his information, that is, that a "pooling" equilibrium arises. Such an equilibrium has the advantage of avoiding the incentive constraints that arise in "separating" equilibria, where information can be inferred from prices. Thus the efficient market hypothesis may well fail if there is imperfect competition. Despite the uniformativeness of prices, the other (competitive) traders are also better off in the pooling equilibrium than in any separating equilibrium, again if one assumes limited variability.

We study the behavior of a large trader with private information about the mean of an asset with a risky return. We argue that if the variability of the return is not too great, typically the trader will find it desirable to ensure that the market price does not reveal his information, that is, that a "pooling" equilibrium arises. Such an equilibrium has the advantage of avoiding the incentive constraints that arise in "separating" equilibria, where information can be inferred from prices. Thus the efficient market hypothesis may well fail if there is imperfect competition. Despite the uniformativeness of prices, the other (competitive) traders are also better off in the pooling equilibrium than in any separating equilibrium, again if one assumes limited variability.

We construct a theory of competitive equilibrium under uncertainty using an entrepreneurial model with historical roots in the work of Knight in the 1920s. Individuals possess labor which they can supply as workers to a competitive labor market or use as entrepreneurs in running a firm. All entrepreneurs have access to the same risky technology and receive all profits from their firms. In the equilibrium, more risk averse individuals become workers while the less risk averse become entrepreneurs. Less risk averse entrepreneurs run larger firms and economy-wide increases in risk aversion reduce the equilibrium wage. A dynamic process of firm entry and exit is stable. The equilibrium is efficient only if all entrepreneurs are risk neutral. Inefficiencies in the number of firms and in the allocation of labor to firms are traced to inefficiencies in the risk allocation caused by institutional constraints on risk trading. In a second best sense which accounts for these constraints, the equilibrium is efficient.

[We construct a theory of competitive equilibrium under uncertainty using an entrepreneurial model with historical roots in the work of Knight in the 1920s. Individuals possess labor which they can supply as workers to a competitive labor market or use as entrepreneurs in running a firm. All entrepreneurs have access to the same risky technology and receive all profits from their firms. In the equilibrium, more risk averse individuals become workers while the less risk averse become entrepreneurs. Less risk averse entrepreneurs run larger firms and economy-wide increases in risk aversion reduce the equilibrium wage. A dynamic process of firm entry and exit is stable. The equilibrium is efficient only if all entrepreneurs are risk neutral. Inefficiencies in the number of firms and in the allocation of labor to firms are traced to inefficiencies in the risk allocation caused by institutional constraints on risk trading. In a second best sense which accounts for these constraints, the equilibrium is efficient.]