Research Seminar 2011-2012

Titles, abstracts and documents :

May 2012, Friday 11: Learning Consumer Tastes through Dynamic Assortments, by Pr. Dorothée Honhon (TU/e Technische Universiteit Eindhoven) (N1, room 115, 3:00pm-4:00pm)

Abstract : How should a firm modify its product assortment over time when learning about consumer tastes? In this paper, we study dynamic assortment decisions in a horizontally differentiated product category for which consumers’ diverse tastes can be represented as locations on a Hotelling line. We presume that the firm knows all possible consumer locations, comprising a finite set, but does not know their probability distribution. We model this problem as a discrete time dynamic program; each period, the firm chooses an assortment and sets prices to maximize the total expected profit over a finite horizon, given its subjective beliefs over consumer tastes. The consumers then choose a product from the assortment that maximizes their own utility. The firm observes sales, which provide censored information on consumer tastes, and updates beliefs in a Bayesian fashion. There is a recurring tradeoff between the immediate profits from sales in the current period (exploitation) and the informational gains to be exploited in all future periods (exploration). We show that one can (partially) order assortments based on their information content and that in any given period the optimal assortment cannot be less informative than the myopically optimal assortment. This result is akin to the well-known ‘stock more’ result in censored newsvendor problems with the newsvendor learning about demand through sales when lost sales are not observable. We demonstrate that it can be optimal for the firm to alternate between exploration and exploitation, and even offer assortments that lead to losses in the current period in order to gain information on consumer tastes. We also develop a Bayesian conjugate model that reduces the state space of the dynamic program and study value of learning using this conjugate model.
April 2012, Wednesday 23: Micro econometric evidence of financing frictions and innovatice activity, by Dr. Amaresh Tiwari (HEC-ULg) (N1, room 320, 12:00pm-2:00pm)
April 2012, Friday 20: Conceptualizing organizational change toward corporate social responsibility: A quad-motor theory, by Pr. François Maon (IESEG School of Management Lille) (N1, room 223, 12:30pm-2:00pm)

Abstract : This article introduces a composite model of organizational change that moves toward corporate social responsibility (CSR), built on a combination of ideal-type theories of change and an existing conceptualization of CSR cultural phases. The result is a quad-motor theory of CSR development in which life cycle, teleological, dialectical, and evolutionary motors of change operate interdependently, depending on the unit of change considered and the level of integration of CSR principles into the company’s culture. This conceptual study supports more comprehensive accounts of the dynamic processes of organizational change toward CSR; it also helps bridge the gap between emerging research into what prompts corporate engagement in CSR and the actual design and implementation of CSR initiatives. Overall, this study offers both a relevant framework for assessing prior research and a structured blueprint to drive ongoing research efforts.
March 2012, Wednesday 21: Do Implicit Barrier MAtter for Globalization?, by Pr. Francesca Carrieri (McGill University, Montreal, Canada) (N1, room 220, 12:30pm-2:30pm)

Abstract : Market liberalization may not result in global pricing or full market integration if implicit barriers are important. We test this proposition for 22 emerging markets using the conditional version of Errunza and Losq (1985) model. We estimate and compare the degree of integration for stocks that are eligible for purchase by foreigners (investible) and those that are not (non-investible). Our results show that local factors are priced for both segments and the implicit barriers are significantly associated with the integration measure. Specifically, better institutions, stronger corporate governance and more transparent markets would jointly contribute to a higher degree of integration by about 15-20 percent.
December 2011, Thursday 7: Three Types of Competitive Facility Location Problems, by Phd. Hande Küçükaydin (ULg) (N1, room 320, 11:00-13:00)
December 2011, Thursday 1: Coordination, Delegation and Organization of Shared Supply Chain Investments under Asymmetric Information, by Pr. Per Agrell (UCL) (N1, room 220, 10:00-12:00)
November 2011, Thuesday 10: Testing for jumps in GARCH models, a robust approach by Pr. Franz Palm (Maastricht University) (N1, room 220, 12:00-14:00)

Abstract : Financial series occasionally exhibit large changes. Assuming that the observed return series consist of a standard normal ARMA-GARCH component plus an additive jump component, we propose a new test for additive jumps in an ARMA-GARCH context. The test is based on standardised returns, where the first two conditional moments are estimated in a robust way. Simulation results indicate that the test has very good finite sample properties, i.e. correct size and much higher proportion of correct jump detection than Franses and Ghijsels’s (1999) test. We apply our test on the YEU-USD exchange rate and find twice as much jumps as Franses and Ghijsels’s (1999) test.
October 2011, Monday 24: Optimisation de la gestion des opérations d’escale sur une plateforme aéroportuaire by Dr. Catherine Mancel (Ecole Nationale de l’Aviation Civile, Toulouse) (N1, room 315, 10:00-12:00)

Abstract : On s’intéresse au problème de la gestion des activités d’escales sur une plateforme aéroportuaire. Les opérations d’escale sont réalisées par différents prestataires de services, à l’aide de véhicules propres à chaque type d’opération. Ces différents intervenants doivent se coordonner de façon à réaliser les escales de chaque avion dans le temps imparti, tout en respectant les contraintes d’ordonnancement des tâches pour chaque avion et les contraintes liées à l’utilisation des véhicules de service. Or, on constate qu’une part importante des retards des vols est générée pendant l’escale des avions à leur poste de stationnement, il est donc intéressant d’étudier ce problème pour tenter de trouver des stratégies permettant de minimiser ces retards. Le problème d’optimisation combinatoire sous-jacent est un problème hybride d’ordonnancement de tâches et de tournée de véhicule qui, à notre connaissance, est très peu étudié dans la littérature. On propose un modèle mathématique puis on explore différentes pistes de résolution en s’appuyant sur une étude comparative de notre problème avec des problèmes académiques. Nous discuterons également du problème de la génération de jeux de données pertinents, nécessaires pour pouvoir évaluer les méthodes de résolution envisagées.