A hybrid simulation optimization method for production planning of dedicated remanufacturing

This paper presents a hybrid cell evaluated genetic algorithm (CEGA) for optimization of the dedicated remanufacturing system with simulation. The paper first summarizes the special characteristics and problems of the dedicated remanufacturing. The paper then proposes a simulation model with a prioritized stochastic batch arrival mechanism, considering factors that affect the total profit. Based on the simulation model, the CEGA algorithm is developed to optimize the production planning and control policies for dedicated remanufacturing. A case study is provided based on the remanufacturing facility located at Austin, USA     

Latin American financial markets

Harvey Arbeláez and Reid Click. 2005. Latin American Financial Markets: Developments in Financial Innovations (Vol. 5). Amsterdam: Elsevier JAI. 445 pages. ISBN: 0‐7623‐1163‐0.     

Jumps in cross‐sectional rank and expected returns: a mixture model

We propose a new nonlinear time series model of expected returns based on the dynamics of the cross‐sectional rank of realized returns. We model the joint dynamics of a sharp jump in the cross‐sectional rank and the asset return by analyzing (1) the marginal probability distribution of a jump in the cross‐sectional rank within the context of a duration model, and (2) the probability distribution of the asset return conditional on a jump, for which we specify different dynamics depending upon whether or not a jump has taken place. As a result, the expected returns are generated by a mixture of normal distributions weighted by the probability of jumping. The model is estimated for the weekly returns of the constituents of the SP500 index from 1990 to 2000, and its performance is assessed in an out‐of‐sample exercise from 2001 to 2005. Based on the one‐step‐ahead forecast of the mixture model we propose a trading rule, which is evaluated according to several forecast evaluation criteria and compared to 18 alternative trading rules. We find that the proposed trading strategy is the dominant rule by providing superior risk‐adjusted mean trading returns and accurate value‐at‐risk forecasts. Copyright © 2008 John Wiley & Sons, Ltd.     

How Much Do Strategic Groups Matter?

Understanding firm heterogeneity is the first step towards explaining the dispersion of profit rates between firms. This paper proposes a framework that distinguishes between three sources of competitiveness, related to three levels of firm heterogeneity, which give rise to industry competencies, strategy-specific competencies and firm-specific competencies. Using data from a Spanish survey we estimate the relative importance of these three sources of heterogeneity. We show that taking the group effect into account significantly differentiates our results from those obtained in previous research. We provide new evidence on the existence of a significant group effect and also an estimate of its relative importance vis á vis firm and industry effects.     

Do Repeated Wildfires Change Homebuyers’ Demand for Homes in High-Risk Areas? A Hedonic Analysis of the Short and Long-Term Effects of Repeated Wildfires on House Prices in Southern California

Unlike most hedonic studies that analyze the effects of a one-time event, this paper analyzes the effects of forest fires that are several years apart in a small geographical area. We find that repeated forest fires cause house prices to decrease for houses located near the fires. We test and reject the hypothesis that the house price reduction from one fire is equal to the house price reduction from a second fire. The first fire reduces house prices by about 10%, while the second fire reduces house prices by nearly 23%, a statistically significant difference. The pattern of these results are robust to several alternative econometric specifications.

Análisis del servicio de Urgencias aplicando teoría de líneas de espera

Those responsible for making decisions in hospitals are increasingly aware of the need to efficiently manage hospital systems. An option for analysis is done by queuing models. In this paper is analyzed the service area ER, in a public hospital applying the concepts and relationships of waiting lines. From the model results, it is concluded that in the emergency department does not have the required minimum number of doctors to allow a steady flow of patients. With the model, the minimum required number of doctors is calculated to meet current and future demand for service with the same service time and the same discipline of service. Analytical models, allowing direct understand the relationships between service demand, number of doctors and patient care priority viewed as a queuing system. The work is useful for administrators and managers of hospital systems.     

Prices and heterogeneous search costs

We study price formation in a model of consumer search for differentiated products in which consumers have heterogeneous search costs. We provide conditions under which a pure‐strategy symmetric Nash equilibrium exists and is unique. Search costs affect two margins—the intensive search margin (or search intensity) and the extensive search margin (or the decision to search rather than to not search at all). These two margins affect the elasticity of demand in opposite directions and whether lower search costs result in higher or lower prices depends on the properties of the search cost density.     

Arrendamiento o compra de inmovilizado utilizando el endeudamiento

This work introduces the VNA (Clear Advantage of the Lease) criterion with the goal of letting any company that wants to incorporate fixed assets into his productive process, know whether it is better to realize it by means of a lease or through a debt-financed purchase. After analyzing the main lease types, the VNA criterion is applied to two different assumptions which also include an approximation to the legal Spanish regulation. Anyway, given its flexibility, the above mentioned criterion can be adapted to different cases and regulations. All kinds of results are obtained in this work, depending on the assumption adopted and on the variability granted to the different parameters used. In this respect, far from making hasty a priori affirmations on the convenience of leasing or buying fixed assets by means of debt, we recommend an ad hoc analysis in every case.     

Market Research for the Optimization of the Consumers Response to the Recent Award of a Protected Geographical Indication to a Local Product,Beans from “La Bañeza-León” (Spain)

Abstract

In Europe several low involvement food products with reduced productions have been awarded with a PGI or PDO during the last few years. The beans from La Bañeza-León (Spain) are an example of this and received a PGI in September 2005. The general objective was to appraise the effect that the award of the PGI to such kinds of food products has in consumers, in order to optimize the managerial and public policies, and to get maximum advantage from the PGI distinction in the commercialization of them. For low involvement products with PGI, the general guidelines should be to keep the prices as low as possible, to develop intensive public information campaigns about the award of the PGI, and to offer the product in medium or high involvement restaurants, in order to reach those consumers willing to pay more for the product, that are mainly in the age range of 36 to 45 years. It is also discussed that the PGI label would have more interest than a private brand. Specifically for beans from “La Bañeza-León,” the PGI Council should urgently tackle a promotional campaign about the product and the PGI award that should reach to most of the consumers in the target markets, taking into account that as the distance from the production area increases the knowledge of the product decreases. This campaign should help the consumer to clearly identify the beans from the PGI by using an attractive logo, and to inform them that the beans from the PGI are superior than substitutive beans in taste and cooking time. Finally, public campaigns that promote the consumption of beans among youth would be necessary.     

Necessity entrepreneurship in Latin America: it´s not that simple

ABSTRACT

Entrepreneurship literature takes for granted the motivation dichotomy; however, this simplistic view have been criticised for several studies because it likely does an injustice to entrepreneurs, particularly Latin America (LA) entrepreneurs. This study seeks to contribute to the body of knowledge on entrepreneurs to better explain the process of entrepreneurs being motivated by necessity. We use the Global Entrepreneurship Monitor (GEM) database for LA countries and develop an econometric model based on a set of variables, including contextual variables. First, we identify three types of entrepreneurial motivation: necessity, opportunity and transition. We then demonstrate that the motivation dichotomy does not represent LA entrepreneurship. Second, we find that necessity-driven entrepreneurship does not necessarily indicate the absence of high growth aspirations because some entrepreneurs in this category have such aspirations. Third, we observe that significant differences exist among entrepreneurs based on context, specifically among necessity-driven entrepreneurs. These findings have practical implications for research on entrepreneurship and for regional development.