Résumé
In economics, incomplete markets are markets in which there does not exist an Arrow–Debreu security for every possible state of nature. In contrast with complete markets, this shortage of securities will likely restrict individuals from transferring the desired level of wealth among states. An Arrow security purchased or sold at date t is a contract promising to deliver one unit of income in one of the possible contingencies which can occur at date t + 1. If at each date-event there exists a complete set of such contracts, one for each contingency that can occur at the following date, individuals will trade these contracts in order to insure against future risks, targeting a desirable and budget feasible level of consumption in each state (i.e. consumption smoothing). In most set ups when these contracts are not available, optimal risk sharing between agents will not be possible. For this scenario, agents (homeowners, workers, firms, investors, etc.) will lack the instruments to insure against future risks such as employment status, health, labor income, prices, among others. In a competitive market, each agent makes intertemporal choices in a stochastic environment. Their attitudes toward risk, the production possibility set, and the set of available trades determine the equilibrium quantities and prices of assets that are traded. In an "idealized" representation agents are assumed to have costless contractual enforcement and perfect knowledge of future states and their likelihood. With a complete set of state contingent claims (also known as Arrow–Debreu securities) agents can trade these securities to hedge against undesirable or bad outcomes. When a market is incomplete, it typically fails to make the optimal allocation of assets. That is, the First Welfare Theorem no longer holds. The competitive equilibrium in an Incomplete Market is generally constrained suboptimal. The notion of constrained suboptimality was formalized by Geanakoplos and Polemarchakis (1986).
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.
Cours associés (6)
FIN-609: Asset Pricing (2011 - 2024)
This course provides an overview of the theory of asset pricing and portfolio choice theory following historical developments in the field and putting emphasis on theoretical models that help our unde
FIN-615: Dynamic Asset Pricing
This course provides an advanced introduction to the methods and results of continuous time asset pricing
FIN-406: Macrofinance
This course provides students with a working knowledge of macroeconomic models that explicitly incorporate financial markets. The goal is to develop a broad and analytical framework for analyzing the
Afficher plus
Séances de cours associées (20)
Détermination des prix de l'État d'équilibre
Explique la détermination des prix de l'état d'équilibre dans la tarification des actifs par le biais de la compensation du marché de la consommation et des contraintes budgétaires.
Aversion au risque et marchés complets
Explore l'aversion au risque, les marchés complets et le comportement optimal dans les modèles de macrofinance.
Pareto Efficience et protection sociale
Explore l'efficacité Pareto, le bien-être social et l'optimisation des prix des actifs sur des marchés complets et incomplets.
Afficher plus
Publications associées (31)
Concepts associés (1)
Marché (économie)
Un marché est l'institution sociale abstraite où se rencontrent l'offre et la demande de biens ou de services. Le marché est ainsi le lieu, physique ou virtuel, où les échanges commerciaux ont lieu. Dans son acception la plus ancienne, un marché est une institution qui accueille un commerce localisé précisément dans l'espace et le temps mais de dimension variable, par exemple les marchés traditionnels, les marchés aux puces et Lloyd's of London.