The performance of active portfolio managers who must comply with a weights constraint is often assessed against a benchmark. The weights constraint is common as the funds are committed by their own prospectus to a minimum (or maximum) portfolio concentration. We characterize the optimal asset allocation and analyze the implications of the weights constraint on the manager's performance and on the relevance of the information ratio. We obtain that because of the weights constraint, at the optimum, the information ratio often decreases when the manager is free to deviate more from the benchmark. 相似文献
This paper presents a model where individuals have imperfect information and there is an opportunity cost of learning. It shows that the endogenous decision to collect costly information before taking an action has a systematic effect on choices. More precisely, consider two alternatives with ex ante identical expected payoff but different variances. The model predicts that, after the learning process is stopped, a majority of individuals will select the alternative with largest payoff-variance. The result persists when agents have multiple sources of information. Applications to entrepreneurial investments, composition of advisory committees, and judicial decision-making are discussed. 相似文献
High-value export-oriented agriculture is today considered as a means of integrating smallholders into the world economy. This paper examines the geographic and organisational changes that have taken place in the fresh pineapple sector over the past 50 years. We begin with a historical analysis of the changes in leadership among producer countries, namely the dethroning of Côte d’Ivoire by Costa Rica. We show that this geographical shift has been accompanied by massive organisational changes: the pineapple sector is increasingly driven by large downstream actors who derive their power from the ability to impose their definition of quality to the whole chain, and from economies of scale and scope. Although varietal innovation plays a key role throughout the period, commercial and logistical innovation are of increasing strategic importance. However, because of the constraints imposed by the concerned supply chains, small farmers risk being excluded or marginalized. 相似文献
The purpose of this article is twofold: (1) to investigate the emotions experienced by banking customers when using live chat services and their impact on positive word-of-mouth intentions; and, (2) to identify which dimensions of e-service quality (accessibility, customer service and support, perceived security/privacy and design) impact these emotions. A survey was conducted with 682 members of a Web-based panel. Findings demonstrate that emotions, both positive and negative, significantly impact word of mouth. Results further reveal that customer service and support followed by design of live chat services mostly influence consumer emotions. On a practical level, the recommendations provided will improve consumer experience and encourage consumers to use live chat services. This is all the more important since such services are now part of the promotion and contribution of a sustainable mode of consumption that is accessible to all.
Over the past decade, the structural analysis of auction data has attracted considerable attention. The structural approach relies on the hypothesis that observed bids are the equilibrium bids of the gametheoretic auction model under consideration. In this paper, we survey econometric methods that have been recently developed for estimating first-price auction models within the private value paradigm. In particular, we focus on two important issues. A first question is to know whether the structural elements of the model, mainly the underlying latent distribution of bidders private values, are identifiable from observations, usually the observed bids. A second issue concerns the estimation of the underlying density. This can be performed through different methods ranging from parametric to nonparametric ones. After a brief review of basic auction models, we first consider the simple first-price auction model with- in the symmetric independent private value paradigm with a nonbinding reserve price. In a second part, more advanced models are considered allowing for a binding reserve price, affiliation among private values, and asymmetry among bidders. The conclusion presents some future lines of research. Depuis une dizaine d'années, I'analyse structurale des mécanismes en jeu dans la conduite des enchères suscite une attention considérable. Cette démarche structurale sefonde sur I'hypothèse selon laquelle les offres observées constituent les offres à l'équilibre d'un modèle d'enchères basé sur la théorie des jeux. Dans le présent exposé, nous pas sons en revue les méthodes économétriques qui ont été mises au point ces derniéres années pour construire des modéles d'enchéres au premier prix dans le cadre du paradigme des valeurs personnelles. Nous nous intéressons en particulier à deux questions importantes: la première est de savoir si les éléments structuraux du modèle, essentiellement la distribution latente sous-jacente des valeurs personnelles des enchérisseurs sont identifiables à partir des observations, c'est-à-dire habituellement les offres observées. La deuxième question concerne l'estimation de la densité sousjacente. Elle peut se faire par différentes méthodes allant des paramétriques au non paramétriques. Après une brève revue des modèles d'enchères de base, nous considérons d'abord le modèle d'enchère, simple au premier prix dans le cadre du paradigme des valeurs personnelles indépendantes symétriques, assorti d'un prix minimum non liant. Dans la seconde partie, nous examinons des modèles plus avancés, autorisant unprix minimum liant, Vaffiliation parmi les valeurs personnelles et I'asymétrie parmi les enchérisseurs. En conclusion, nous proposons quelques avenues de recherches futures. 相似文献
The nonparametric approach Data Envelopment Analysis is used in order to measure individual technical inefficiency. Different models are evaluated using a 1991 FADN data set of French pig farms. Organic nitrogen is considered as a byproduct of animal breeding. Used as plant nutrient, organic manure becomes an input in crop production which is pollutant when excessive amounts enter surface and groundwater. In the latter case, the usual hypothesis of strong disposability of organic nitrogen is refuted because the elimination of pollution is costly. In this paper, we introduce a hypothesis of weak disposability of organic nitrogen and compare the technical efficiency measures obtained with and without this assumption. Then, using the duality between the restricted cost function and the input-output distance function and following Färe and Primont (1995), we derive a shadow price of organic nitrogen which can be compared to the unit cost of different existing manure treatments. 相似文献
We use the Marimon and Zilibotti (Econ J 109: 266–291, 1999) circle model and we endogenize the choice of the degree of specialization
of jobs. We show that an increase in unemployment benefits not only reduces the mismatch of talents (as in Marimon and Zilibotti),
but it also raises the degree of specialization of jobs. This reinforces the productivity enhancing effects of unemployment
benefits.
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Uncertainty about ex post realized values is an inherent component in many auction environments. In this article, we develop a structural framework to analyze auction data subject to ex post uncertainty as a pure risk. We consider a low‐price sealed‐bid auction model with heterogeneous bidders' preferences and ex post uncertainty. The uncertainty can be common to all bidders or idiosyncratic. We derive the model restrictions and study nonparametric and semiparametric identification of the model primitives under exogenous and endogenous participation. We then develop multistep nonparametric and semiparametric estimation procedures in both cases. 相似文献