The recent crisis was characterized by massive illiquidity. This paper reviews what we know and don't know about illiquidity and all its friends: market freezes, fire sales, contagion, and ultimately insolvencies and bailouts. It first explains why liquidity cannot easily be apprehended through a single statistic, and asks whether liquidity should be regulated given that a capital adequacy requirement is already in place. The paper then analyzes market breakdowns due to either adverse selection or shortages of financial muscle, and explains why such breakdowns are endogenous to balance sheet choices and to information acquisition. It then looks at what economics can contribute to the debate on systemic risk and its containment. Finally, the paper takes a macroeconomic perspective, discusses shortages of aggregate liquidity, and analyzes how market value accounting and capital adequacy should react to asset prices. It concludes with a topical form of liquidity provision, monetary bailouts and recapitalizations, and analyzes optimal combinations thereof; it stresses the need for macro-prudential policies. (JEL E44, G01, G21, G28, G32, L51)

Pigovian taxation of externalities has limited appeal if the tortfeaser has insufficient resources to pay the damage when it occurs. To defend Pigovian taxation in the presence of judgement-proof agents, its proponents point at the many institutions extending liability to third parties. Yet little is known about the validity of Pigou's analysis in this context. The paper analyses the costs and benefits of extended liability and investigates whether full internalization is called for in the presence of agency costs between potential tortfeasers and providers of guarantees. Its contribution is two-fold. It first shows that the better the firms' corporate governance and the stronger their balance sheet, the more closely taxes should track the corresponding externality. It then develops the first analysis of extended liability when guarantors themselves may be judgement-proof, and the extension of liability may give rise to further externalities. Relatedly, it derives the curvature of the optimal taxation of externalities in a multi-plant firm.

The paper is a first attempt at modelling the idea of group reputation as an aggregate of individual reputations. A member's current incentives are affected by his past behaviour and, because his track record is observed only with noise, by the group's past behaviour as well. The paper thus studies the joint dynamics of individual and collective reputations and derives the existence of stereotypes from history dependence rather than from a multiplicity of equilibria or from the existence of a common trait as is usually done in the literature. It shows that new members of an organization may suffer from an original sin of their elders long after the latter are gone, and it derives necessary and sufficient conditions under which group reputations can be rebuilt. Last, the paper applies the theory to analyse when a large firm can maintain a reputation for quality.

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 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

[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.]

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.