In a number of interesting environments, dynamic screening involves positive selection: in contrast with Coasian dynamics, only the most motivated remain over time. The paper provides conditions under which the principal's commitment optimum is time consistent and uses this result to derive testable predictions under permanent or transient shocks. It also identifies environments in which time consistency does not hold despite positive selection, and yet simple equilibrium characterizations can be obtained.

The paper first develops an economic analysis of the concept of shareholder value, describes its approach and discusses some open questions. It emphasizes the relationship between pledgeable income, monitoring and control rights using a unifying and simple framework. The paper then provides a first and preliminary analysis of the concept of the stakeholder society. It investigates whether the managerial incentives and the control structure described in the first part can be modified so as to promote the stakeholder society. It is shown that the implementation of the stakeholder society strikes three rocks: dearth of pledgeable income, deadlocks in decision-making, and lack of clear mission for management. While it fares better on those three grounds, shareholder value generates biased decision-making; the paper analyzes the costs and benefits of various methods of protecting noncontrolling stakeholders: covenants, exit options, flat claims, enlarged fiduciary duty.

The paper takes stock of the advances and directions for research on the incomplete contracting front. It first illustrates some of the main ideas of the incomplete contract literature through an example. It then offers methodological insights on the standard approach to modeling incomplete contracts; in particular it discusses a tension between two assumptions made in the literature, namely rationality and the existence of transaction costs. Last, it argues that, contrary to what is commonly argued, the complete contract methodology need not be unable to account for standard institutions such as authority and ownership; and it concludes with a discussion of the research agenda.

[The first part of this paper considers the interaction between productive and nonproductive savings in a growing economy. It employs an overlapping generations model with capital accumulation and various types of rents, and gives necessary and efficient conditions for the existence of an aggregate bubble. The second part is a series of thoughts on the definition, nature, and consequences of asset bubbles. First, it derives some implications of bubbles for tests of asset pricing. Second, it demonstrates the specificity of money as an asset and shows that there is a fundamental dichtotomy in its formalization. Third, it discusses inefficiencies of price bubbles. Fourth, it shows that the financial definition of a bubble is not satisfactory for some assets.]

The first part of this paper considers the interaction between productive and nonproductive savings in a growing economy. It employs an overlapping generations model with capital accumulation and various types of rents, and gives necessary and sufficient conditions for the existence of an aggregate bubble. The second part is a series of thoughts on the definition, nature, and consequences of asset bubbles. First, it derives some implications of bubbles for tests of asset pricing. Second, it demonstrates the specificity of money as

This paper considers the possibility of static and dynamic speculation when traders have rational expectations. Its central theme is that, unless traders have different priors or are able to obtain insurance in the market, speculation relies on inconsistent plans, and thus is ruled out by rational expectations. Its main contribution lies in the integration of the rational expectations equilibrium concept into a model of dynamic asset trading and in the study of the speculation created by potential capital gains. Price bubbles and their martingale properties are examined. It is argued that price bubbles rely on the myopia of traders and that they disappear if traders adopt a truly dynamic maximizing behavior.

A principal has private information that directly affects her agent's payoff (i.e., "common values" obtains). The authors analyze their relationship as a three-stage game: (1) the principal proposes a contract; (2) the agent accepts or rejects; and (3) the contract is executed. They show that the equilibrium outcomes are the allocations that weakly Pareto dominate the allocation maximizing the payoff of each "type" of the principal within the class of incentive-compatible allocations ensuring the agent his reservation utility irrespective of his beliefs about the principal's type. The authors also characterize the equilibria that are immune to renegotiation.

The authors analyze the principal-agent relationship when the principal has private information as a three-stage game: contract proposal, acceptance/refusal, and contract execution. They assume that the information does not directly affect the agent's payoff (private values). Equilibrium exists and is generically locally unique. Moreover, it is Pareto optimal for the different types of principal. The principal generically does strictly better than when the agent knows her information. Equilibrium allocations are the Walrasian equilibria of an "economy" where the traders are different types of principal and "exchange" the slack on the agent's individual rationality and incentive compatibility constraints.