Real indeterminacy of equilibria in a sunspot economy with inside money

Summary In a two-period sunspot economy with inside money andS possible realizations of the sunspot, we prove that, genetically in the space of utility functions, there areS — 1 degrees of real indeterminacy. This result generalizes the previously known result for sunspot models that, generically in endowments, there is at least one degree of real indeterminacy. The proof involves showing that generically the equilibrium allocation is different across states for some household. This property allows us to perturb the utility function in a simple way and to apply standard transversality arguments to prove our main theorem.We would like to thank David Cass, Atsushi Kajii, Michael Mandler and Paolo Siconolfi for helpful discussions.     

La réaction des titres canadiens aux changements dans les prévisions de bénéfices comptables*

Résumé. Cette première étude canadienne des prévisions de bénéfices comptables effectuées par les analystes financiers et publiées par l'Institutional Brokers Estimate System (IBES) s'intéresse aux révisions dans les prévisions moyennes de bénéfice par action, pour 159 à 188 entreprises, de 1985 à 1987. L'étude utilise une approche résiduelle pour analyser l'évolution des rendements lors de l'annonce des révisions les plus importantes. Les principaux résultats sont les suivants. Premièrement, l'investisseur qui disposerait des révisions au début du mois où elles sont transmises aux abonnés pourrait réaliser des rendements anormaux. Deuxièmement, l'abonné qui transige sur la base de l'information qu'il reçoit pourrait également développer des stratégies de placement qui généreraient des rendements excédentaires importants. Il devrait pour cela tenir compte simultanément de l'importance relative des révisions, du secteur d'activité des entreprises et de l'horizon des prévisions. Troisièmement, lorsque les prévisions sont publiées, l'information contenue dans les changements importants dans les prévisions a déjà été partieliement anticipée par le marché. Ce résultat confirme ceux obtenus aux États-Unis et en Grande-Bretagne. Enfin, les révisions importantes coïncident avec une période de rendements anormaux. On ne peut cependant pas mettre en évidence de lien de causalité entre la divulgation de ces révisions et les rendements anormaux, car la date où l'information parvient aux utilisateurs ne peut ètre déterminée avec précision. Ces résultats ne varient pas selon le modèle de prévision des rendements utilisé. Ils ne constituent vraisemblablement pas une marque d'inefficience du marché canadien, car l'acquisition, le traitement et l'analyse des données, ainsi que les frais de transaction représentent des coûts importants qui limitent les rendements nets de stratégies de placement basées sur ces données.     

Providers’ affiliation,insurance and collusion

This paper provides a theoretical analysis of the benefits for an insurance company to develop its own network of service providers when insurance fraud is characterized by collusion between policyholders and providers. In a static framework without collusion, exclusive affiliation of providers allows insurance companies to recover some market power and to lessen competition on the insurance market. This entails a decrease in the insured’s welfare. However, exclusive affiliation of providers may entail a positive effect on customers’ surplus when insurers and providers are engaged in a repeated relationship. In particular, while insurers must cooperate to retaliate against a fraudulent provider under non-exclusive affiliation, no cooperation is needed under exclusive affiliation. In that case, an insurer is indeed able to reduce the profit of a malevolent provider by moving to collusion-proof contracts when collusion is detected, and this threat may act as a deterrent for fraudulent activities. This possibility may supplement an inefficient judicial system: it is thus a second-best optimal anti-fraud policy.     

Ambiguity Aversion and Incompleteness of Financial Markets

It is widely thought that incomes risks can be shared by trading in financial assets. But financial assets typically carry some risk idiosyncratic to them, hence, disposing incomes risk using financial assets will involve buying into the inherent idiosyncratic risk. However, standard theory argues that diversification would reduce the inconvenience of idiosyncratic risk to arbitrarily low levels. This paper shows that this argument is not robust: ambiguity aversion can exacerbate the tension between the two kinds of risks to the point that classes of agents may not want to trade some financial assets. Thus, theoretically, the effect of ambiguity aversion on financial markets is to make the risk sharing opportunities offered by financial markets less complete than it would be otherwise.     

The impact of MERCOSUR on trade of Brazilian states

We consider the impact of MERCOSUR on trade among Brazilian states and on trade by Brazilian states with MERCOSUR and the rest of the world. We use a theoretically founded gravity model to shed light on MERCOSUR??s possible creation and diversion effects as well as its ??preference erosion?? effect on trade among Brazilian states. Using data on interstate trade over a 4-year period, including 1?year prior to the MERCOSUR period (1991), we deliver empirical evidence at state level with a focus on the impact of MERCOSUR which can vary across Brazilian regions. We show that MERCOSUR increased Brazilian states?? trade with member countries, but had no effect on either interstate trade or Brazilian states?? trade with third countries. The paper finds that MERCOSUR??s impact varies across Brazilian regions and that Center West region did not benefit from the integration to MERCOSUR. We use an estimation method dealing better with the traditional issue of zero trade values and heteroskedasticity than ordinary least squares does.     

Social interaction and economic organization: Toward an integrative microeconomic model

In the context of increasingly complex economies, with information more and more complicated to handle, social interaction may allow spontaneous co-operation and be more efficient than market or state regulations to overcome co-ordination and information problems. This article provides a theoretical model that compares three “pure forms” of economic organization: state-controlled production, unregulated market, and voluntary organization. We model the behavior of agents who are embedded in a social structure that is characterized by three parameters: the intensity of socialization, the size of individual social space, and the overall level of trust in society. We then study how social interaction parameters influence the relative efficiency of the three different forms of organization.     

Carbon leakages: a general equilibrium view

The effectiveness of unilateral action to curb carbon emissions has been dismissed because of possible “carbon leakages”, this referring to the rise of emissions in non-participating countries. This paper offers a general equilibrium (GE) exploration of the key mechanisms and factors underlying the size of carbon leakages. We developed a two-region, two-goods simplified GE framework, incorporating three types of fossil fuels (coal, oil and low-carbon energy), international trade and capital mobility. The model was designed to make tractable extensive multidimensional sensitivity analysis. The results suggest that the coal supply elasticity plays a critical role, while substitution elasticities between traded goods and international capital mobility appear relatively less influential. The shape of the production function also matters for the size of the leakages. Confirming the results obtained with large computable GE models, for a wide range of parameters’ values, carbon leakages appear to be small. Therefore, the argument that unilateral carbon abatement action taken by a large group of countries (such as the Annex 1 group) is flawed by significant carbon leakages is not supported by our sensitivity analysis. The likelihood of small leakages favours in fact the formation of a worldwide coalition to stabilise climate change.     

The two sides of proximity in industrial clusters: The trade-off between process and product innovation

According to the literature on industrial districts, the proximity of small firms operating in a similar sector can lead to several positive externalities, which enhance collective efficiency. We investigate this assumption by building a microeconomic model in which a set of small firms trades off two opposite effects. First, the closer they are to each other, the more they can share fixed costs or pool risks, and the more they can innovate on more efficient processes. Second, the closer they are, the less diverse is their cognitive environment, and the less they innovate on products. We find that there is a “bell-shaped relationship” between proximity and the firms' performance. Moreover, equilibrium configurations tend to produce too much proximity from the consumers' and the workers' point of view, but too few proximity from the firms' point of view.     

Foreign aid and trade reform: Evidence from ACP-EU data

Beside traditional motives of giving – namely, altruism and donors’ self-interest, foreign aid also serves to encourage poor countries to liberalize trade. In this paper, I use recent foreign aid data from 15 European donors to 45 African, Caribbean and Pacific countries (ACP) to assess the importance of each motive. Although all the motives are important, their relative importance varies from one sub-group of donors to another. In particular, big donors such as France, Germany and the United Kingdom seem to weight more their commercial interests than other European donors; besides, recipient needs appear to be less important. Contrary to other European donors, international cooperation, measured by the correlation in the votes at the United Nations General Assemblies influences their decision to allocate aid to ACP recipients. This last finding probably reflects their relatively high political power in international fora. Finally, I introduce a dummy variable for economic partnership agreement (EPA) and find that donors do not give to support trade liberalization per se. However, large donors give more aid to ACP exporters of raw materials that engage in the EPA. This result implies that foreign aid is a device to secure access to raw materials.