The Design and efficiency of loyalty rewards

The goal of this paper is to reexamine the optimal design and efficiency of loyalty rewards in markets for final consumption goods. While the literature has emphasized the role of loyalty rewards as endogenous switching costs (which distort the efficient allocation of consumers), in this paper I analyze the ability of alternative designs to foster consumer participation and increase total surplus. First, the efficiency of loyalty rewards depend on their specific design. A commitment to the price of repeat purchases can involve substantial efficiency gains by reducing price-cost margins. However, discount policies imply higher future regular prices and are likely to reduce total surplus. Second, firms may prefer to set up inefficient rewards (discounts), especially in those circumstances where a commitment to the price of repeat purchases triggers Coasian dynamics.

The Division problem with voluntary participation

The division problem consists of allocating a given amount of an homogeneous and perfectly divisible good among a group of agents with single-peaked preferences on the set of their potential shares. A rule proposes a vector of shares for each division problem. The literature has implicitly assumed that agents will find acceptable any share they are assigned to. In this paper we consider the division problem when agents' participation is voluntary. Each agent has an idiosyncratic interval of acceptable shares where his preferences are single-peaked. A rule has to propose to each agent either to not participate or an acceptable share because otherwise he would opt out and this would require to reassign some of the remaining agents' shares. We study a subclass of efficient and consistent rules and characterize extensions of the uniform rule that deal explicitly with agents' voluntary participation.

On Cooperative solutions of a generalized assignment game: limit theorems to the set of competitive equilibria

We study two cooperative solutions of a market with indivisible goods modeled as a generalized assignment game: Set-wise stability and Core. We first establish that the Set-wise stable set is contained in the Core and it contains the non-empty set of competitive equilibrium payoffs. We then state and prove three limit results for replicated markets. First, the sequence of Cores of replicated markets converges to the set of competitive equilibrium payoffs when the number of replicas tends to infinity. Second, the Set-wise stable set of a two-fold replicated market already coincides with the set of competitive equilibrium payoffs. Third, for any number of replicas there is a market with a Core payoff that is not a competitive equilibrium payoff.

EU cohesion aid to Spain: a data set. Part I: 2000-06 planning period

In this paper we construct a data set on EU cohesion aid to Spain during the planning period 2000-06. The data are disaggregated by region, year and function and attempt to approximate the timing of actual executed expenditure on assisted projects.

Indirect likelihood inference

Given a sample from a fully specified parametric model, let Zn be a given finite-dimensional statistic - for example, an initial estimator or a set of sample moments. We propose to (re-)estimate the parameters of the model by maximizing the likelihood of Zn. We call this the maximum indirect likelihood (MIL) estimator. We also propose a computationally tractable Bayesian version of the estimator which we refer to as a Bayesian Indirect Likelihood (BIL) estimator. In most cases, the density of the statistic will be of unknown form, and we develop simulated versions of the MIL and BIL estimators. We show that the indirect likelihood estimators are consistent and asymptotically normally distributed, with the same asymptotic variance as that of the corresponding efficient two-step GMM estimator based on the same statistic. However, our likelihood-based estimators, by taking into account the full finite-sample distribution of the statistic, are higher order efficient relative to GMM-type estimators. Furthermore, in many cases they enjoy a bias reduction property similar to that of the indirect inference estimator. Monte Carlo results for a number of applications including dynamic and nonlinear panel data models, a structural auction model and two DSGE models show that the proposed estimators indeed have attractive finite sample properties.

On the stability of the optimal value and the optimal set in optimization problems

The paper develops a stability theory for the optimal value and the optimal set mapping of optimization problems posed in a Banach space. The problems considered in this paper have an arbitrary number of inequality constraints involving lower semicontinuous (not necessarily convex) functions and one closed abstract constraint set. The considered perturbations lead to problems of the same type as the nominal one (with the same space of variables and the same number of constraints), where the abstract constraint set can also be perturbed. The spaces of functions involved in the problems (objective and constraints) are equipped with the metric of the uniform convergence on the bounded sets, meanwhile in the space of closed sets we consider, coherently, the Attouch-Wets topology. The paper examines, in a unified way, the lower and upper semicontinuity of the optimal value function, and the closedness, lower and upper semicontinuity (in the sense of Berge) of the optimal set mapping. This paper can be seen as a second part of the stability theory presented in [17], where we studied the stability of the feasible set mapping (completed here with the analysis of the Lipschitz-like property).

Generalized descriptive set theory and classification theory

Descriptive set theory is mainly concerned with studying subsets of the space of all countable binary sequences. In this paper we study the generalization where countable is replaced by uncountable. We explore properties of generalized Baire and Cantor spaces, equivalence relations and their Borel reducibility. The study shows that the descriptive set theory looks very different in this generalized setting compared to the classical, countable case. We also draw the connection between the stability theoretic complexity of first-order theories and the descriptive set theoretic complexity of their isomorphism relations. Our results suggest that Borel reducibility on uncountable structures is a model theoretically natural way to compare the complexity of isomorphism relations.

An efficient use of virtualization in grid/cloud environments

Grid is a hardware and software infrastructure that provides dependable, consistent, pervasive, and inexpensive access to high-end computational resources. Grid enables access to the resources but it does not guarantee any quality of service. Moreover, Grid does not provide performance isolation; job of one user can influence the performance of other user’s job. The other problem with Grid is that the users of Grid belong to scientific community and the jobs require specific and customized software environment. Providing the perfect environment to the user is very difficult in Grid for its dispersed and heterogeneous nature. Though, Cloud computing provide full customization and control, but there is no simple procedure available to submit user jobs as in Grid. The Grid computing can provide customized resources and performance to the user using virtualization. A virtual machine can join the Grid as an execution node. The virtual machine can also be submitted as a job with user jobs inside. Where the first method gives quality of service and performance isolation, the second method also provides customization and administration in addition. In this thesis, a solution is proposed to enable virtual machine reuse which will provide performance isolation with customization and administration. The same virtual machine can be used for several jobs. In the proposed solution customized virtual machines join the Grid pool on user request. Proposed solution describes two scenarios to achieve this goal. In first scenario, user submits their customized virtual machine as a job. The virtual machine joins the Grid pool when it is powered on. In the second scenario, user customized virtual machines are preconfigured in the execution system. These virtual machines join the Grid pool on user request. Condor and VMware server is used to deploy and test the scenarios. Condor supports virtual machine jobs. The scenario 1 is deployed using Condor VM universe. The second scenario uses VMware-VIX API for scripting powering on and powering off of the remote virtual machines. The experimental results shows that as scenario 2 does not need to transfer the virtual machine image, the virtual machine image becomes live on pool more faster. In scenario 1, the virtual machine runs as a condor job, so it easy to administrate the virtual machine. The only pitfall in scenario 1 is the network traffic.

El comportamiento penalmente relevante en el delito de defraudación tributaria: una propuesta político-criminal

El sistema tributario es fundamental en el Estado social y democrático de Derecho, pues el ejercicio y efectivo disfrute de muchos derechos fundamentales depende del correcto funcionamiento de la actividad tributaria. Además de esto, la situación económica actual demanda una adecuada política en contra del fraude tributario, lo que necesariamente implica analizar si el modelo penal vigente es el más adecuado para enfrentar el fraude fiscal. Teniendo en cuenta que muchas de las características de la criminalidad tributaria no son exclusivas de un país, pues ésta trasciende habitualmente las fronteras de los países por medio del recurso a empresas multinacionales o la localización de empresas en “paraísos fiscales”, el análisis del fraude tributario no debe limitarse al examen jurídico del modelo legislativo español, debiendo trascender a un estudio de política criminal que vincula consideraciones criminológicas y jurídicas. En consecuencia, en esta investigación se propone un análisis que no se reduce a los debates exclusivamente jurídicos. Se busca, además, efectuar un examen que tenga por fundamento una perspectiva criminológica y de Law in action a fin de evaluar críticamente la respuesta a la criminalidad tributaria por parte del modelo de regulación penal vigente en España. Esta orientación permitirá una más amplia comprensión del fenómeno de la criminalidad tributaria, así como de las categorías jurídicas adecuadas político criminalmente para su prevención. Este estudio interdisciplinario nos conducirá, al final de la investigación, tanto a proponer la interpretación del modelo de legislación penal vigente, como una reforma al mismo que pretenda solucionar algunos de los problemas de prevención que a lo largo de la investigación se señalan.

Segimon Comas : importància i contextualització històrica d'un universitari i acadèmic del set-cents

Contextualització històrica dels inicis de l'Acadèmia de Bones Lletres al segle XVIII, i un dels seus artífexs, Segimon Comas.

Construcció i explotació d'un magatzem de dades per a l'anàlisi estadístic dels resultats del Campionat de Fórmula 1

En els darrers anys les organitzacions han anat agafant consciència de la importància de la gestió de la seva informació. D'aquesta necessitat d'organitzar les pròpies dades d'una forma coherent i eficient per al seu anàlisi sorgeixen els magatzems de dades. El projecte "Construcció i explotació d'un magatzem de dades per a l'anàlisi estadístic dels resultats del Campionat de Fórmula 1" s'emmarca dins aquest context i te com a objectiu el disseny d'un magatzem de dades per a cobrir les necessitats del Institut Català d'Esports de Motor (ICEM) en la gestió de les seves dades referents a la Fórmula 1. En aquest projecte s'han executat les diferents fases necessàries per a la creació d'un nou magatzem. En primer lloc s'ha fet l'anàlisi de requeriments i de les dades disponibles. A continuació s'ha fet el disseny i la implementació física del magatzem de dades. Seguidament s'ha procedit amb l'extracció, transformació i càrrega de dades originals (ETL) i per finalitzar s'han creat els informes. Com a resultat s'han obtingut una sèrie d'informes per a ser consumits de manera immediata pels usuaris del ICEM. Aquests informes han de permetre l'anàlisi de les dades d'una forma senzilla i àgil. A més s'ha implementat un sistema d'actualització automàtic de les dades que per al manteniment de la informació del magatzem.La implementació del magatzem de dades s'ha fet sobre una base de dades Oracle 10g Express Edition i els informes s'ha dissenyat amb l'eina Oracle Discoverer. Per a l'automatització de les dades s'ha fet servir a més visual basic script i l'eina de càrrega SQL*Loader.

Fuzzy set Theory and Quantum Chemistry

Es discuteixen breument algunes consideracions sobre l'aplicació de la Teoria delsConjunts difusos a la Química quàntica. Es demostra aqui que molts conceptes químics associats a la teoria són adequats per ésser connectats amb l'estructura dels Conjunts difusos. També s'explica com algunes descripcions teoriques dels observables quàntics espotencien tractant-les amb les eines associades als esmentats Conjunts difusos. La funciódensitat es pren com a exemple de l'ús de distribucions de possibilitat al mateix temps queles distribucions de probabilitat quàntiques

When a data set can be considered compositional?

Traditionally, compositional data has been identified with closed data, and the simplex has been considered as the natural sample space of this kind of data. In our opinion, the emphasis on the constrained nature ofcompositional data has contributed to mask its real nature. More crucial than the constraining property of compositional data is the scale-invariant property of this kind of data. Indeed, when we are considering only few parts of a full composition we are not working with constrained data but our data are still compositional. We believe that it is necessary to give a more precisedefinition of composition. This is the aim of this oral contribution

Efficient learning of reactive robot behaviors with a Neural-Q_learning approach

The purpose of this paper is to propose a Neural-Q_learning approach designed for online learning of simple and reactive robot behaviors. In this approach, the Q_function is generalized by a multi-layer neural network allowing the use of continuous states and actions. The algorithm uses a database of the most recent learning samples to accelerate and guarantee the convergence. Each Neural-Q_learning function represents an independent, reactive and adaptive behavior which maps sensorial states to robot control actions. A group of these behaviors constitutes a reactive control scheme designed to fulfill simple missions. The paper centers on the description of the Neural-Q_learning based behaviors showing their performance with an underwater robot in a target following task. Real experiments demonstrate the convergence and stability of the learning system, pointing out its suitability for online robot learning. Advantages and limitations are discussed