Risk Aversion over Incomes and Risk Aversion over Commodities

This note determines the precise connection between an agent's attitude towards income risks and his attitude over risks in the underlying consumption space. Our results follow a general mathematical theory connecting the curvature properties of an objective function with the ray-curvature properties of its dual.risk aversion, concavity, duality

Special issue of the Journal of Global Optimization on Applications to Economics

A forthcoming special issue of Journal of Global Optimization contains a number of articles that may be interesting to economic theorists. Table of Contents: A.M. Bagirov and A.M. Rubinov Global optimization of marginal functions with applications to economic equilibrium K. Cechlarova, M. Dahm and V. Lacko Efficiency and stability in a discrete model of country formation I.V. Evstigneev and S.D. Flam Sharing Nonconvex Costs M.E. Jerrell and W.A. Campione Global optimization of econometric functions R. John The concave nontransitive consumer C. Le Van, F.H. Page, Jr. and M.H. Wooders Arbitrage and Equilibrium in Economies with Externalities G.G. Malcolm and B.S. Mordukhovich Pareto optimality in nonconvex economies with infinite-dimensional commodity spaces A. Soubeyran and H. Stahn Price Behaviors on Networks: Some General Results for Two-way Networks A. Villar On the efficiency of market equilibrium in production economies

REPRESENTING GAMES AS COALITION PRODUCTION ECONOMIES WITH PUBLIC GOODS

In this paper we introduce a new approach to representing both TU-games and NTU-games as special economic structures. Instead of representing a game as a market – an exchange economy with concave utility functions – as in the extant literature, we represent an arbitrary game as a coalition production economy with a public good. The economy provides an indirect description of the game. Our model uses the idea of a social planner or arbitrager who, through arbitrage on productive activities, seeks to minimize the net cost of providing the public good subject to the constraint that the society satisfies its reservation welfare level. Note that in constrast to the prior literature on representing games as economic structures, we require neither that the game be balanced nor that there are large numbers of players. Our approach to representing a game as an economic structure uses techniques from consumer demand theory and, in particular, the notion of a compensated demand correspondence. The main results of this paper exhibit a relationship between cooperative game theory and consumer demand theory.

Learning from Errors

We present a model of learning in which agents learn from errors. If an action turns out to be an error, the agent rejects not only that action but also neighboring actions. We find that, keepng memory of his errors, under mild assumptions an acceptable solution is asymptotically reached. Moreover, one can take advantage of big errors for a faster learning.Learning, errors, fixed points, normal form games, best reply functions

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Minimization of quadratic functions on convex sets without asymptotes

The classical Frank and Wolfe theorem states that a quadratic function which is bounded below on a convex polyhedron $P$ attains its infimum on $P$. In this joint work with D. Noll and W. Sosa we investigate whether more general classes of convex sets can be identified which have this Frank-and-Wolfe property. We show that the intrinsic characterizations of Frank-and-Wolfe sets hinge on asymptotic properties of these sets.Non UBCUnreviewedAuthor affiliation: Universitat Autònoma de BarcelonaFacult

Mission d'appui au laboratoire de recherches vétérinaires et zootechniques de Farcha (Tchad)

A la demande du laboratoire de Farcha, cette mission avait pour objectif d'identifier des pistes de recherche concernant la sécurisation des systèmes pastoraux, de discuter des perspectives de partenariat dans les différents domaines retenus, de se focaliser sur le rôle des dromadaires dans la dynamique des systèmes pastoraux et de proposer des pistes pour des projets au plan national et au plan régional dans le cadre du PRASAC. Les principales conclusions de la mission se résument en 5 points: (i) Evaluer la place du dromadaire dans l'économie de l'élevage tant au plan des ménages qu'au plan national, (ii) Mesurer l'impact des changements climatiques sur la dynamique des systèmes pastoraux basés sur l'élevage camelin, (iii) Explorer les voies d'une valorisation des produits de l'élevage camelin (lait et viande), (iv) Mettre en oeuvre les réseaux adéquats pour évaluer le poids des maladies émergentes chez le dromadaire face aux changements climatiques et la modification de leurs écosystèmes, (v) Développer une véritable expertise tchadienne en matière de camélologie et de développement de l'élevage camelin. (Résumé d'auteur