Agreement theorem for neo-additive beliefs

In this paper, we extend Aumann’s (Ann Stat 4:1236–1239, 1976) probabilistic agreement theorem to situations in which agents’ prior beliefs are represented by a common neo-additive capacity. In particular, we characterize the family of updating rules for neo-additive capacities, which are necessary and sufficient for the impossibility of “agreeing to disagree” on the values of posterior capacities as well as on the values of posterior Choquet expectations for binary acts. Furthermore, we show that generalizations of this result to more general acts are impossible.     

Merger selection,evidence provision,and the timing of merger control

Merger control impacts the type of merger projects that are submitted, as well as the information provided by the merging parties upon assessment. In this paper, we consider the outcomes in terms of selection of merger types and evidence provision of alternative timings for merger review, pre- or postconsummation of the merger. We show that the selection effect induced by the ex post merger review is welfare-improving due to the deterrence of the most anticompetitive merger projects. In contrast, the welfare impact of evidence provision under ex post assessment is ambiguous. Balancing these two effects makes possible the welfare comparison between the ex ante and the ex post merger policy enforcement.     

The Nonequivalence of Import and Export Quotas in Strategic Equilibrium

The authors use a standard general‐equilibrium trade model to show that export and import policies are not symmetric in the equilibrium of a strategic game with quotas. It is assumed that N (identical) large countries, without cooperation, set their import (or export) quotas to maximize domestic welfare. It is shown that the equilibrium in which all countries use import quotas differs from, and is superior to, the equilibrium in which countries use export quotas. The difference arises because the elasticity of the residual foreign export supply schedule differs between the two equilibria. The authors also study the properties of the sequential equilibrium of the game. In a simultaneous‐move game, each country is indifferent as to whether it uses an import or export quota, given the policy of the other country. However, in a sequential‐move game, the first mover will prefer to use an import quota rather than an export quota.     

Low-Price Low-Capacity Traps and Government Intervention in the Québec Hog Market

This paper investigates the marketing of a primary commodity produced by competitive producers that sell to a single downstream processor. There is a significant lag between production and marketing decisions made by producers. If a credible price commitment cannot be made before producers make their output decision, it is a dominant strategy for the processor to buy producers' output at the world price adjusted for transportation costs. Producers fully anticipate this partial holdup ex ante and adjust production accordingly. When the processor's capacity is binding ex post, the equilibrium is described as a low‐price, low‐capacity trap. Under a specific condition, the processor finds it advantageous to credibly commit to a price increment before producers make their output decision. The ensuing equilibrium is Pareto‐superior to the no‐commitment equilibrium. We argue that the Québec hog/pork industry has experienced such a situation in the past few years. Government intervention is justified even if the processor has committed to a price increment. The modeling of strategic interactions between the government and the processor reveals that their price increments are strategic substitutes. However, given that the processor's (government's) payoff is increasing with the government's (processor's) price increment, the first‐mover advantage entails committing early to a low‐price increment to force one's rival to offer a high‐price increment. Cet article analyse la mise en marché d'un produit primaire vendu par des producteurs preneurs de prix à un seul et unique transformateur. Les décisions de production et de mise en marché sont séparées dans le temps. Si le transformateur ne peut pas s'engager à payer un certain prix avant que les producteurs prennent leur décision de production, alors la stratégie dominante du transformateur est d'offrir aux producteurs le prix mondial diminué par les coûts de transport. Les producteurs anticipant ce hold‐up partiel et réduisent leur production en conséquence. Lorsque le transformateur est confrontéà une contrainte de capacité ex post, les producteurs et le transformateur sont piégés dans un équilibre de « petit prix et petit volume ». Si une condition est respectée, il peut être avantageux pour le transformateur d'offrir un supplément aux producteurs avant leur décision de production. L'équilibre qui s'en suit constitue alors une amélioration au sens de Pareto. Nous soumettons que l'industrie porcine québécoise a vécu pareille expérience durant les dernières années. L'intervention du gouvernement demeure justifiée même si le transformateur s'est commis à payer un supplément. En fait, les interventions du transformateur et du gouvernement sont des substituts stratégiques. Puisque le gain du transformateur (gouvernement) croit avec le supplément offert par le gouvernement (transformateur), il y a un avantage àêtre le premier à se commettre à payer un faible supplément, tant pour le transformateur que pour le gouvernement, pour ainsi forcer l'autre partie à offrir un supplément plus généreux.     

The Collusion-deterring Effect of Pre-attributed Supplies and the Hog Auction in Quebec

The hog/pork industry in Quebec has been going through major institutional changes since 1989, the year an electronic auction was put in place to market all of the hogs in the province. Because the auction's ability to generate high prices did not meet the expectations of hog producers, the pure auction system was replaced by a hybrid one in 1994. In this system, most of the hog supply was pre-attributed to processors at a negotiated price based on the US. price while the remainder of the provincial supply of hogs was sold through the auction. In this paper, we investigate how a seemingly inefficient marketing mechanism like pre-attributions can increase the efficiency of a usually efficient mechanism like an auction. We present theoretical arguments regarding the sustainability of collusion under the pure auction and hybrid systems in addition to analyzing auction prices with modern time series tools.     

Sarmanov Family of Bivariate Distributions for Multivariate Loss Reserving Analysis

The correlation among multiple lines of business plays a critical role in aggregating claims and thus determining loss reserves for an insurance portfolio. We show that the Sarmanov family of bivariate distributions is a convenient choice to capture the dependencies introduced by various sources, including the common calendar year, accident year, and development period effects. The density of the bivariate Sarmanov distributions with different marginals can be expressed as a linear combination of products of independent marginal densities. This pseudo-conjugate property greatly reduces the complexity of posterior computations. In a case study, we analyze an insurance portfolio of personal and commercial auto lines from a major U.S. property-casualty insurer.     

Comparaison de la rentabilité des systèmes conventionnels et biologiques en production laitière au Québec

De la banque de données AGRITEL, 336 fermes conventionnelles et 16 fermes biologiques, spécialisées en production laitière, sont sélectionnées. Sept groupes (dont un est biologique) sont alors formés correspondant à des concepts de production différents. Les groupes defermes conventionnelles correspondent à des niveaux d'intrants particulièment élevés (haut niveau d'intrants) ou faibles (bas niveau d'intrants), ainsi qu'à des niveaux de production élevés @roduction intensive) oufaibles (production extensive), pour le troupeau ou pour l'ensemble de l'entreprise.
Les fermes biologiques parviennent à des résultats technico-économiques et financiers au moins aussi bons que les fermes avec des rendements élevés (intensifs). En revanche, même si les concepts de production sont proches, les différences de rendement et de rentabilité sont assez nettes (souvent signcatives) entre le groupe biologique et les groupes extensifs ou à bas niveau d'intrants. Les entreprises biologiques sont plus équilibrtés et la prédominance de la production laitière est moindre. Les coûts de main-d'œuvre sont toutefois plus élevés que la plupart des groupes d'entreprises conventionnelles.
Cette étuaè nous laisse croire qu'il est possible d'amtéliorer la rentabilité des fermes extensives et à bas niveau d'intrants, dont les concepts de production se rapprochent de ceux de l'agriculture biologique.