Design of homogenous territorial units: a methodological proposal

One of the main questions to solve when analysing geographically added information consists of the design of territorial units adjusted to the objectives of the study. In fact, in those cases where territorial information is aggregated, ad-hoc criteria are usually applied as there are not regionalization methods flexible enough. Moreover, and without taking into account the aggregation method applied, there is an implicit risk that is known in the literature as Modifiable Areal Unit Problem (MAUP) (Openshaw, 1984). This problem is related with the high sensitivity of statistical and econometric results to different aggregations of geographical data, which can negatively affect the robustness of the analysis. In this paper, an optimization model is proposed with the aim of identifying homogenous territorial units related with the analyzed phenomena. This model seeks to reduce some disadvantages found in previous works about automated regionalisation tools. In particular, the model not only considers the characteristics of each element to group but also, the relationships among them, trying to avoid the MAUP. An algoritm, known as RASS (Regionalization Algorithm with Selective Search) it also proposed in order to obtain faster results from the model. The obtained results permit to affirm that the proposed methodology is able to identify a great variety of territorial configurations, taking into account the contiguity constraint among the different elements to be grouped.

Spanish unemployment: normative versus analytical regionalisation procedures

In applied regional analysis, statistical information is usually published at different territorial levels with the aim of providing information of interest for different potential users. When using this information, there are two different choices: first, to use normative regions (towns, provinces, etc.), or, second, to design analytical regions directly related with the analysed phenomena. In this paper, provincial time series of unemployment rates in Spain are used in order to compare the results obtained by applying two analytical regionalisation models (a two stages procedure based on cluster analysis and a procedure based on mathematical programming) with the normative regions available at two different scales: NUTS II and NUTS I. The results have shown that more homogeneous regions were designed when applying both analytical regionalisation tools. Two other obtained interesting results are related with the fact that analytical regions were also more stable along time and with the effects of scale in the regionalisation process. Keywords: Unemployment, normative region, analytical region, regionalisation. JEL Codes: E24, R23, C61.

Research networks and scientific production in Economics: The recent spanish experience (WP)

This paper studies Spanish scientific production in Economics from 1994 to 2004. It focuses on aspects that have received little attention in other bibliometric studies, such as the impact of research and the role of scientific collaborations in the publications produced by Spanish universities. Our results show that national research networks have played a fundamental role in the increase in Spanish scientific production in this discipline

Decomposing the Rural-Urban Differential in Student Achievement in Colombia Using PISA Microdata

Despite the large number of studies that draw on Programme for International Student Assessment (PISA) microdata in their analyses of the determinants of educational outcomes, no more than a few consider the relevance of geographical location. In going some way to rectify this, our paper examines the differences in educational outcomes between students attending schools in rural areas and those enrolled in urban schools. We use microdata from the 2006 and 2009 PISA survey waves for Colombia. The Colombian case is particularly interesting in this regard due to the structural changes suffered by the country in recent years, both in terms of its political stability and of the educational reform measures introduced. Our descriptive analysis of the data shows that the educational outcomes of rural students are worse than those of urban students. In order to identify the factors underpinning this differential, we use the Oaxaca-Blinder decomposition and then exploit the time variation in the data using the methodology proposed by Juhn-Murphy-Pierce. Our results show that most of the differential is attributable to family characteristics as opposed to those of the school. From a policy perspective, our evidence supports actions addressed at improving conditions in the family rather than measures of positive discrimination of rural schools.Blinder-Oaxaca decompositio

Is the wage curve formal or informal? Evidence for Colombia (WP)

The objective of this paper is to analyse the existente or not of a wage curve in Colombia, paying special attention to the differences between formal and informal workers, an issue that has been systematically ignored in the wage curve literature. The obtained results using microdata from the Colombian Continuous Household Survey (CHS) between 2002 and 2006 show the existence of a wage curve with a negative slope for the Colombian economy. Using information on metropolitan areas, the estimates of the elasticity of individual wages to local unemployment rates was -0.07, a value that is very close to those obtained for other countries. However, the disaggregation of statistical information for formal and informal workers has shown significant differences among both groups of workers. In particular, for the less protected groups of the labour market, informal workers (both men and women), a high negatively sloped wage curve was found. This result is consistent with the conclusions from efficiency wage theoretical models and should be taken into account when analysing the functioning of regional labour markets in developing countries

Supervised regionalization methods: A survey

This paper reviews almost four decades of contributions on the subject of supervised regionalization methods. These methods aggregate a set of areas into a predefined number of spatially contiguous regions while optimizing certain aggregation criteria. The authors present a taxonomic scheme that classifies a wide range of regionalization methods into eight groups, based on the strategy applied for satisfying the spatial contiguity constraint. The paper concludes by providing a qualitative comparison of these groups in terms of a set of certain characteristics, and by suggesting future lines of research for extending and improving these methods

La producción científica en el ámbito de la Economía y Empresa en España. Rankings de las universidades españolas en términos de producción, productividad, calidad e impacto en el período 1994-2003.

En este trabajo se analiza la situación de las publicaciones científicas en Economía y Empresa en España en el decenio 1994-2003. En concreto se analizan la producción de artículos, la productividad por investigador, la calidad de las publicaciones y su impacto (citas) y se elaboran rankings de las universidades españolas. Los principales resultados apuntan a unos niveles de producción científica que evolucionan de manera creciente en los últimos años. Esta mejora se debe al incremento de la plantilla y, sobre todo, al incremento de su productividad

La investigación regional en España. Rankings de países, instituciones y autores en ciencia regional y urbana para el período 1991-2000

Este trabajo analiza cual ha sido la evolución de la investigación en ciencia regional y urbana en España en el período 1991-2000 situándola en el contexto internacional. Para ello, se elaboran rankings de países, autores e instituciones en función de las publicaciones realizadas en una muestra de nueve revistas internacionales ampliamente reconocidas dentro de este campo. Los resultados muestran que la mejora en la posición relativa a nivel internacional encontrada por otros autores para el conjunto de la investigación española en economía también se produce en el contexto de la investigación económica regional y urbana De hecho, hay un claro aumento de la presencia a nivel internacional de los autores e instituciones españolas motivado en buena medida por un incremento de las publicaciones de autores con tradición en la investigación en ciencia regional y urbana pero también por la irrupción con fuerza de 'nuevos' autores

La investigación regional en España: un análisis bibliométrico

Este trabajo analiza cual ha sido la evolución de la investigación en ciencia regional y urbana en España en el período 1991-2000 situándola en el contexto internacional. Para ello, se elaboran rankings de países, autores e instituciones en función de las publicaciones realizadas en una muestra de nueve revistas internacionales ampliamente reconocidas dentro de este campo. Los resultados muestran que la mejora en la posición relativa a nivel internacional encontrada por otros autores para el conjunto de la investigación española en economía también se produce en el contexto de la investigación económica regional y urbana De hecho, hay un claro aumento de la presencia a nivel internacional de los autores e instituciones españolas motivado en buena medida por un incremento de las publicaciones de autores con tradición en la investigación en ciencia regional y urbana pero también por la irrupción con fuerza de 'nuevos' autores

Fault Detection of Wind Turbine Induction Generators through Current Signals and Various Signal Processing Techniques

Producción CientíficaIn the wind industry (WI), a robust and effective maintenance system is essential. To minimize the maintenance cost, a large number of methodologies and mathematical models for predictive maintenance have been developed. Fault detection and diagnosis are carried out by processing and analyzing various types of signals, with the vibration signal predominating. In addition, most of the published proposals for wind turbine (WT) fault detection and diagnosis have used simulations and test benches. Based on previous work, this research report focuses on fault diagnosis, in this case using the electrical signal from an operating WT electric generator and applying various signal analysis and processing techniques to compare the effectiveness of each. The WT used for this research is 20 years old and works with a squirrel-cage induction generator (SCIG) which, according to the wind farm control systems, was fault-free. As a result, it has been possible to verify the feasibility of using the current signal to detect and diagnose faults through spectral analysis (SA) using a fast Fourier transform (FFT), periodogram, spectrogram, and scalogram