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 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.

Autocratic regimes, democratic majorities, private platforms, and religious or professional organizations can achieve social control by managing the flow of information about individuals’ behavior. Bundling the agents’ political, organizational, or religious attitudes with information about their prosocial conduct makes them care about behaviors that they otherwise would not. The incorporation of the individuals’ social graph in their social score further promotes soft control but destroys the social fabric. Both bundling and guilt by association are most effective in a society that has weak ties and is politically docile.

When will solidarity, which emerges spontaneously from the fear of spillovers, be reinforced through contracting? The optimal pact between countries that differ substantially in their probability of distress is a simple debt contract with market financing, a borrowing cap, but no joint liability. While joint liability augments total surplus, the borrowing country cannot compensate the deep-pocket guarantor. By contrast, the optimal pact between two countries symmetrically exposed to shocks with an arbitrary correlation is a simple debt contract with joint liability, provided that shocks are sufficiently independent, spillovers sufficiently large, liquidity needs moderate, and available sanctions sufficiently tough.

Industrial organization studies the exercise and control of market power. To this purpose, it builds models that capture the essence of the situation. The predictions of the model can then be tested econometrically and possibly in the lab or the field. In the end, the reasonableness of, and robustness to modeling assumptions and the quality of empirical fit determine how confident economists are in making recommendations to public decision-makers for intervention, and to companies for the design of their business model. Industrial organization has a long tradition: first theoretical, with the work of French “engineer-economists” Antoine Augustin Cournot (1838) and Jules Dupuit (1844); then policy-oriented with the enactment of the Sherman Act (1890) and subsequent legislation; then descriptive with the studies of the Harvard school (“Structure-Conduct-Performance”) comforting and refining the antitrust drive; and finally skeptical with the Chicago school. The Chicago school correctly pointed out the lack of underlying theoretical doctrine and went on to cast doubt on the whole edifice. It however did not develop an alternative antitrust doctrine, perhaps because