Rafael Suárez-Vega

Location models and GIS tools for retail site location

Test notes - published with permission of Nicola C. Original version was at www.plymouth.ac.uk

Discretization and resolution of the (r|X p )-medianoid problem involving quality criteria

In this paper an extension of the (r|Xp)-medianoid on networks introduced by Hakimi (1983) is studied. In this extension the customer considers not only the distance but some characteristics of the facilities such as store size, quality of service and parking space. A new firm wants to establishr new facilities which have to compete with thep facilities that already exist in the market. The entry firm wants to find their locations and characteristics to maximize profits. Three different customer choice rules (binary, partially binary and proportional preferences) are considered. Some discretization results are obtained and a resolution procedure is proposed. The problem is solved combining a global search algorithm based on a branch and bound procedure with some combinatorial heuristics (greedy, interchange, and tabu search). Some computational experiences are presented.

Journal topic citation potential and between-field comparisons: The topic normalized impact factor

The journal impact factor is not comparable among fields of science and social science because of systematic differences in publication and citation behavior across disciplines. In this work, a source normalization of the journal impact factor is proposed. We use the aggregate impact factor of the citing journals as a measure of the citation potential in the journal topic, and we employ this citation potential in the normalization of the journal impact factor to make it comparable between scientific fields. An empirical application comparing some impact indicators with our topic normalized impact factor in a set of 224 journals from four different fields shows that our normalization, using the citation potential in the journal topic, reduces the between-group variance with respect to the within-group variance in a higher proportion than the rest of indicators analyzed. The effect of journal self-citations over the normalization process is also studied.

Spatial and environmental characteristics of rural tourism lodging units

The geographical characteristics of the site where a rural house is located determine its tourist affluence. By using a hedonic prices model, this paper estimates the influence of some spatial and environmental variables in the rental prices of rural houses in Gran Canaria, Spain. Geographic information systems (GIS) data are used to measure the geographical attributes associated with the house, such as the land use and the nearby population density. Other factors traditionally included in hedonic models are also analysed, such as the structural characteristics of the house and distance to some points of interest. The methodology allows us to obtain an estimation of the economic value of the location and environment surrounding a rural house. Spatial econometrics was applied to study the correlation of rental prices. Results indicate that environmental diversity and remoteness positively affect prices. Some recommendations are extracted from the results, which could help to orientate the tourist diversification policies applied to the island.

The Influence of Remoteness and Isolation in the Rural Accommodation Rental Price among Eastern and Western Destinations

Experiencing the context of a rural environment is the fundamental aspect of rural travel. In order to estimate quantitative influences of the rural environment, this paper proposes to proxy rurality through two indicators: isolation and remoteness. The estimation of a hedonic pricing model with the use of both Geographic Information Systems and spatial econometrics allows obtaining the specific influence of these factors on rural lodging room prices. The methodology is applied to two tourist destinations with similar characteristics from Eastern (Taiwan) and Western (Spain) cultures. Results show that visitors’ preferences for isolation are significant but differ between these two regions. The main reasons that explain this divergence are population density differences between origin and destination, domination of international versus domestic visitors, and the intrinsic destination characteristics and perceived image. Managerial recommendations on how to emphasize the factors in the promotion of accommodation services are derived from the present study.

The use of GIS tools to support decision-making in the expansion of chain stores

This article deals with a network competitive localization problem in which a firm seeks to determine the location of a new facility, which competes with all the facilities operating in the market, both belonging to the same firm and to the competing firms. In this context, two frequently conflicting objectives are involved: maximization of the total market share captured by the firm and minimization of market share losses for its existing facilities due to being captured by the new facility (cannibalization). We formulate the location problem as a multi-objective optimization model. Some GIS tools that provide some maps representing the market share and the cannibalization effect are proposed. This allows for the visualization of the effects produced by the opening of a new facility in the market and the trade-offs between the objectives. Finally, the advantages of using these tools have been shown by means of an application to a real data case.

An approach to the author citation potential: measures of scientific performance which are invariant across scientific fields

The citation potential is a measure of the probability of being cited. Obviously, it is different among fields of science, social science, and humanities because of systematic differences in publication and citation behaviour across disciplines. In the past, the citation potential was studied at journal level considering the average number of references in established groups of journals (for example, the crown indicator is based on the journal subject categories in the Web of Science database). In this paper, some characterizations of the author’s scientific research through three different research dimensions are proposed: production (journal papers), impact (journal citations), and reference (bibliographical sources). Then, we propose different measures of the citation potential for authors based on a proportion of these dimensions. An empirical application, in a set of 120 randomly selected highly productive authors from the CSIC Research Centre (Spain) in four subject areas, shows that the ratio between production and impact dimensions is a normalized measure of the citation potential at the level of individual authors. Moreover, this ratio reduces the between-group variance in relation to the within-group variance in a higher proportion than the rest of the indicators analysed. Furthermore, it is consistent with the type of journal impact indicator used. A possible application of this result is in the selection and promotion process within interdisciplinary institutions, since it allows comparisons of authors based on their particular scientific research.

Locating a supermarket using a locally calibrated Huff model

The Huff model is one of the most frequently used models in the field of retail distribution. Traditionally, parameters reflecting the effect of size and distance on determining the customers’ purchase probabilities in this model have been assumed constant along the study area. Applying some transformations on the Huff model formulation, these parameters can be calculated by means of ordinary least squares (OLS). In this paper, we used a local regression model, the geographically weighted regression model, instead of the usual global OLS model, with the aim of considering spatial nonstationarity in the model parameters. The estimated capture for a store was calculated by replacing global parameters with local ones. We present an application in which parameters showed spatial nonstationarity. The location of a new store was analysed too. We conclude that, for this case, the local model fits better than the global one. Moreover, the local model can provide individual information about customer preferences that global models ignore.

Assessing the Spatial and Environmental Characteristics of Rural Tourism Lodging Units Using a Geographical Weighted Regression Model

This paper presents a methodology to identify some factors influencing on the tourism market and not usually included in empirical analyses, such as those related to environment and location. The traditional quantitative analysis of spatially varying relationship assumes that the interdependence among variables measured at different locations is constant over the space. This assumption does not fit the data when the analysed variable presents spatial dependence. To face this problem, Geographical Weighted Regression (GWR) may be considered. The methodology proposed in this paper combines a genetic algorithm to automatically select the factors that best explain the dependent variable and GWR to determine the local estimations of the coefficient of regressors. A hedonic price model to analyse the rural tourism market in the island of La Palma (Canary Islands, Spain) was estimated in the study case. The results show that significant regressors are not homogeneously distributed throughout the island. Instead of a constant value, maps of values of the coefficients were obtained. These maps may be helpful to householders in order to implement local actions based on the attributes of the rental price of every house and estimate the economic returns of new rural houses sited in specific areas of the island.

Pareto Optimal Allocation and Price Equilibrium for a Duopoly with Negative Externality

A spatial competition model involving decisions made by consumers and firms is proposed. A regulating agent assigns the demand, taking into account the price, transport and externality cost, and minimizing the joint consumer cost to obtain a Pareto optimal allocation. Assuming the Pareto optimal allocation, firms fix prices in order to maximize the profit. An equilibrium problem is studied and some results are presented. The problem and results are illustrated with an example.