Agents expect to trade with each other infinitely often, but face a temporal absence of a coincidence of wants when they meet. Only loans and/or money can facilitate exchange. In small close-knit economies, enduring trade relationships are valued and loans are optimal. In larger economies, with limited communication, information concerning repayment of loans diffuses too slowly to deter agents from reneging unless loans are severely restricted in magnitude. Money has no such redeemability problems, but if Clower constraints bind, loans help supplement money purchases so that both become essential. Roles of various institutions and the historical evolution of media of exchange are explained.

I consider an agency model in which an agent, having acquired private post‐contract predecision information, is allowed to breach the contract by paying the principal predetermined damages. The relationship of this model to the standard no‐breach agency model is demonstrated and I argue that simplifying the analysis by restricting attention to no‐breach models may yield incorrect conclusions. The shape of an optimal breach contract is then discussed and it is demonstrated that an optimal contract cannot include a severance payment. Next, I consider an alternative contractual arrangement whereby the agent may purchase access to private information prior to contracting. In this case, all the advantages of the breach institution are maintained, while possible exogenous (legal) restrictions on damage payments are avoided. The paper concludes by suggesting implications the study may have for legal research on contracts and judicial systems. Résumé. L'auteur étudie un modèle de relation de mandataire dans lequel le mandataire, ayant acquis de l'information privée après la signature du contrat et avant la prise de décision, est en droit de mettre fin au contrat en réglant au mandant les dommages établis au préalable. L'auteur démontre la relation entre ce modèle et le modèle standard sans convention de rupture et soutient que le fait de simplifier l'analyse en se bornant à étudier les modèles sans convention de rupture peut mener à des conclusions inexactes. La forme du contrat optimal comportant une convention de rupture est ensuite traitée et l'auteur démontre qu'un contrat optimal ne peut inclure d'indemnité de rupture. Il analyse ensuite une disposition contractuelle de rechange selon laquelle le mandataire peut acheter l'accès à de l'information privée avant de s'engager. Dans ce cas, tous les avantages de la convention de rupture sont maintenus, alors que les restrictions exogènes (légales) possibles relativement au règlement de dommages sont évitées. L'auteur conclut en donnant une idée des conséquences que pourrait avoir cette étude pour la recherche en droit portant sur les contrats et les systèmes judiciaires.

The purpose of this paper is to provide a link between the various multivariate tests of asset pricing and a performance measure for asset sets. The paper includes a unified summary of various F tests for mean-variance efficiency, intersection, and spanning for sets and subsets of financial assets. Both the risk-free asset and no risk-free asset environments are discussed. These tests are then related to the concept of potential performance for asset sets. The potential performance measure can be viewed as an extension of the Sharpe performance measure for single portfolios. The economic intuition behind the tests is that the multivariate tests of portfolio efficiency, intersection, and spanning are tests of zero potential performance at particular margins between the asset or portfolio subset and the full asset set.

A model is produced in which labor contracts that prespecify (unindexed) nominal wage payments arise endogenously. These contracts function as a self-selection mechanism. Under appropriately different attitudes toward price-level risk (which can either arise directly from preferences or be induced by different patterns of asset holdings), nominal contracts allow high-productivity workers to signal their type by their willingness to accept unindexed contracts. This explanation of nominal contracts does not require that money be used in any particular set of transactions, and nominal contracts enhance the risk faced by all parties accepting them.

A real business cycle model is constructed in which workers are heterogeneous and privately informed about their own productive abilities. The model is structured so that interesting cycles cannot arise in the absence of the informational asymmetry. In the presence of this asymmetry, the model produces cyclical fluctuations that are consistent with features of observed business cycles. Hours behavior of individuals is also consistent with micro evidence. In addition, the model gives rise to equilibrium unemployment of labor. The determination of equilibrium unemployment rates, hours levels, and output are integrally related in the analysis.

[This article analyzes the volume of trade in a multiperiod noisy rational expectations model. When traders receive private signals at the first trading date and are allowed a second round of trade, two types of equilibria exist. In the first, traders do not learn about the average private signal from the second round of trade, and all trade takes place at the first date. In the second, traders do learn from the second round, and trade thus takes place at both the first and second dates. The article characterizes volume when a public signal is disclosed at the second date.]

A breadwinner's demand for life insurance depends on the demographic structure of his or her household. The author captures the relationship by extending Menahem E. Yaari's life insurance framework to include the preferences of all household members explicitly. In many households, the insured is the husband and the beneficiaries are his wife and offspring. Their demand for insurance of the husband's life is derived from a life cycle model in which income is uncertain. The results are intuitively appealing in that they describe the explicit calculation made by purchasers of life insurance. Empirical estimates based on observed life insurance ownership also are encouraging.