Existence of marginal pricing equilibria in economies with externalities and non-convexities

We consider a general equilibrium model with externalities and non-convexities in production. The consumption sets, the preferences of the consumers and the production possibilities are represented by set-valued mappings to take into account possibility of external effects. There is no convexity assumption on the correspondences of production. We propose a definition of the marginal pricing rule, which generalizes the one used in the model without externality and, which satisfies a continuity assumption with respect to the external effect.We prove the existence of general equilibria under assumptions which allow us to encompass together the works on economies with externalities and convex conditional production sets, and those on marginal pricing equilibria in economies without externalities. We provide examples to illustrate the definition of the marginal pricing rule and to show the difference with the standard case.     

Effectiveness of brand placement: New insights about viewers

Since traditional media have become saturated, the technique of product placement has been attracting growing interest. This research explores new insights concerning viewers' reactions during a second viewing of a movie. A sample of 3532 French viewers of DVDs has been used to link the way the movie was chosen, viewed and appreciated (or not) with a spontaneous brand placement recall, the day after the film was watched at home. Results make a contribution to strengthening professionals' interest in the technique, and to adding to academic knowledge of the topic. A first viewing of the movie at the cinema improves brand placement recall, as does watching the movie at home on a large home cinema screen. Such an improvement also occurs when a DVD movie is chosen either because of the movie director or when the viewer likes the movie.     

Estimating Demand Response with Panel Data

In this paper, we extend to panel data the iterated linear least squares estimator of Blundell and Robin (in J Appl Econometrics 14: 209–232 1999). It is shown to be consistent when total expenditure and regression residuals are correlated, either because of simultaneity or because of unobserved heterogeneity. We propose separate tests for these two effects. Monte Carlo experiments are then conducted and the estimator is applied to data drawn from a French Consumer Panel.     

Existence and optimality of oligopoly equilibria in linear exchange economies

Summary. We consider a linear exchange economy and its successive replicas. We study the notion of Cournot-Walras equilibrium in which the consumers use the quantities of commodities put on the market as strategic variables. We prove that, generically, if the number of replications is large enough but finite, the competitive behaviour is an oligopoly equilibrium. Then, under a mild condition, which may be interpreted in terms of market regulation and/or market activity, we show that any sequence of oligopoly equilibria of successive replica economies converges to the Walrasian outcome and furthermore that every oligopoly equilibrium of large, but finite, replica is Pareto optimal. Consequently, under the same assumptions on the fundamentals of the economy, one has an asymptotic result on the convergence of oligopoly equilibria to the Walras equilibrium together with a generic existence result for the Cournot-Walras. Received: June 20, 2002; revised version: November 20, 2002 RID="*" ID="*" Part of this paper was written while the second author was visiting the Universidad de Vigo. The support of the department of mathematics is gratefully acknowledged. Correspondence to: J.M. Bonnisseau     

Bargaining over an uncertain outcome:¶the role of beliefs

We study the Nash bargaining solution of a problem in which two agents bargain over an uncertain outcome. Under the assumptions of risk neutrality and of constant absolute risk aversion, we study the way that the solution varies, ex ante, when we vary the beliefs of one agent. Changing an agent's beliefs in a way that makes them “more distant” from the other agent's beliefs makes the second agent better off. Received: 10 May 2001 / Accepted: 22 August 2001     

Non-existence of Duopoly Equilibria: A Simple Numerical Example

We give a simple example to the non-existence of duopoly equilibrium in pure strategies in an economy with two goods and two types of consumers. This extends also the discussion on the incentive for trade in an oligopolistic framework initiated in Cordella and Gabszewicz (1998).     

Is agricultural policy aiming at the wrong target?

Is agricultural policy aiming at the wrong target? Modern political decision makers stress the benefits to be derived from a more market oriented agriculture. For this purpose, they are ready to grant guaranteed decoupled farmer income almost without precedent. They may have lost sight of the true historical reason for which the links between the market and agriculture had been severed during the 1930s, namely the market's inability, in the specific case of agriculture, to transmit relevant information between producer and consumer. In this context, ‘traditional’ agricultural policies may have provided more benefits for consumers than is usually acknowledged, and ‘new’ policies may result in more detrimental effects than expected. La politique agricole se trompe‐t‐elle de cible? A ? heure actuelle, les décideurs politique mettent ? accent sur les bénéfices à attendre de mesure visant a faire orienter ? agriculture par le marché, et sont prêts, pour cela, à accorder aux agriculteurs une garantie de revenu presque sans contre‐partie. Ce faisant, ils semblent avoir perdu de vue la raison pour laquelle ? agriculture avait été déconnectée du marché dans les années 30, à savoir ? inaptitude du marché, dans le cas précis de ? agriculture, à transmettre des informations pertinentes entre les producteurs et les consommateurs. Dans ce contexte, il se peut que les bénéfices des politiques ‘traditionnelles’ aient été beaucoup grands qu'on ne ? admet généralement, tandis que les politiques ‘nouvelles’ seraient susceptibles engendrer plus ?‘effets négatifs qu’on ne s'y attend. Verfolgt die Agrarpolitik ein falsches Ziel? Die politischen Entscheidung sträger von heute heben die Vorteile hervor, die sich aus einer mehr marktorientierten Landwirtschaft ableiten lassen. Daher sind sie bereit, garantierte entkoppelte Einkommenszahlungen an Landwirte zu gewähren, obwohl es dafür noch nahezu keine Erfahrungen gibt. Möglicherweise haben sie den wahren historischen Grund übersehen, der zu einer Abkehr marktwirtschaftlicher Reglungen für die Landwirtschaft in den 1930ern geführt hat. Es war ein Marktversagen bei der Informationsweitergabe im landwirtschaftlichen Bereich zwischen Produzenten und Verbraucher festzustellen. Wird dieser Effekt berücksichtigt, so haben die ‘traditionellen’ landwirtschaftlichen Politikmaßnahmen möglicherweise mehr Vorteile für den Verbraucher gebracht als im allgemeinen angenommen, und ‘neue’ Politikmaßnahmen haben möglicherweise mehr Nachteile als angenommen.