Firms’ growth, size and age: a nonparametric approach

This paper offers empirical evidence of firm failure rates as well as the mean of the distribution of realized growth rates, distinguishing between the sample of non-failing firms and the sample of all firms, failing and non-failing. Attention is directed at identifying a set of characteristics, in particular the size and age of firms, systematically related to the patterns of firm growth and exit, using a panel of Spanish manufacturing firms. The two main contributions of the paper are the use of nonparametric techniques and the analysis of issues ignored in other studies like the regression-to-the-mean bias and the measurement of learning effects. We find evidence that failure rates and the mean growth rate of successful firms decline with size and age. When failing firms are integrated, there are no significant differences in the mean growth rate across the age and size of firms. Regression-to-the-mean does not prove to be a substantial factor behind the negative relationship between size and growth of surviving firms

Firms´productivity and the export market: a nonparametric approach

This paper examines total factor productivity differences between exporting and nonexporting firms. These differences are documented on the basis of a sample of Spanish manufacturing firms over the period 1991-1996 drawn from the ESEE. The paper also examines two complementary explanations for the superior productivity of exporting firms: 1) the market selection hypothesis, and 2) the learning hypothesis. Nonparametric tests are implemented for testing these hypothesis. Results indicate clearly higher levels of productivity for exporting firms than for non-exporting firms. Evidence favours the hypothesis of self-selection of more efficient firms into the export market. However there is little evidence that these efficiency gains are supportive of the learning-by-exporting hypothesis

The Scope, Scale and Locational Preferences of Spanish Multinationals

This paper examines the relationship between firms’ heterogeneity and their multinational activity. We examine the scope and the scale of multinational firms following the insights of Yeaple’s (2009) model. The goal of the paper is to contribute to a better understanding of the activity of Spanish multinationals using a sample of Spanish multinational firms. Our dataset is built from two databases, SABI and ORBIS, both from the Bureau van Dijk. Our results confirm that more productive firms have a greater multinational activity in terms of both the scope (the number of foreign markets where they invest) and the scale (the volume of local sales by subsidiaries in foreign markets). The structure of Spanish multinational firms’ activity is also analysed from the perspective of host country characteristics (GDP, population, distance and language) using standard gravity equations. Country characteristics that are positively associated (GDP and common language) with the volume of multinational activity are negatively related to the productivity of firms that go abroad. This asymmetry also holds for bilateral characteristics as distance that appears negatively associated with the level of multinational activity

Las decisiones de localización, alcance y escala de las empresas multinacionales españolas

This research has been partially funded by the Spanish Ministry of Economy and Competitiveness (project ECO2014-52051-R and ECO2017-82445-R) and by the Autonomous Region of Madrid through project S2015HUM-3417 (INNCOMCON-CM), co-funded by the European Social Fund (European Union). The authors benefited from presentations at the 4th PhD-Student Workshop on Industrial and Public Economics (Reus, 2016), the Conference on International Economics (La Coruña, 2016) and especially from suggestions from Andrés Barge.This paper examines the relationship between firms’ heterogeneity and their multinational activity. We examine the scope and the scale of multinational firms following the insights of Yeaple’s (2009) model. The goal of the paper is to contribute to a better understanding of the activity of Spanish multinationals using a sample of Spanish multinational firms. Our dataset is built from two databases, SABI and ORBIS, both from the Bureau van Dijk. Our results confirm that more productive firms have a greater multinational activity in terms of both the scope (the number of foreign markets where they invest) and the scale (the volume of local sales by subsidiaries in foreign markets). The structure of Spanish multinational firms’ activity is also analysed from the perspective of host country characteristics (GDP, population, distance and language) using standard gravity equations. Country characteristics that are positively associated (GDP and common language) with the volume of multinational activity are negatively related to the productivity of firms that go abroad. This asymmetry also holds for bilateral characteristics as distance that appears negatively associated with the level of multinational activity.En este trabajo se analiza la relación entre la heterogeneidad de las empresas españolas y su actividad multinacional contrastando las predicciones del modelo de Yeaple (2009). Se utiliza una base de datos de empresas multinacionales españolas fusionando dos bases de datos, SABI y ORBIS. Los resultados confirman que las empresas más productivas tienen una mayor actividad multinacional tanto en términos de alcance (número de mercados extranjeros donde las empresas matrices invierten) y de escala (el volumen de las ventas de las subsidiarias en los mercados extranjeros). La estructura de la actividad de las empresas multinacionales también se analiza desde la perspectiva de las características del país receptor (PIB, población, distancia, lengua común…) usando ecuaciones de gravedad. Las características del país que están positivamente relacionadas (PIB y lengua común…) con el volumen de la actividad multinacional presentan una relación negativa con la productividad de las empresas que operan en el exterior. Este efecto asimétrico también se produce para otras variables como la distancia que está negativamente asociada con la actividad multinacional y positivamente con la productividad de las empresas multinacionales.DecanatoFac. de Ciencias Económicas y EmpresarialesTRUEMinisterio de Economía y Competitividad (MINECO)Comunidad de Madridunpu

Mercury and selenium binding biomolecules in terrestrial mammals (Cervus elaphus and Sus scrofa) from a mercury exposed area

Acknowledgements The authors are grateful to Junta de Comunidades de Castilla-La Mancha (PCC-05-004-2, PAI06-0094, PCI-08-0096, PEII09-0032-5329) and the Ministerio de Economía y Competitividad (CTQ2013-48411-P) for financial support. M.J. Patiño Ropero acknowledges the Junta de Comunidades de Castilla-La Mancha for her PhD. fellowship.Peer reviewedPostprin

Reciclado de residuos cerámicos en materiales absorbentes acústicos

The scope of this investigation is to develop a material mainly composed (80% w/w) of ceramic wastes that can be applied in the manufacture of road traffic noise reducing devices. The characterization of the product has been carried out attending to its acoustic, physical and mechanical properties, by measuring the sound absorption coefficient at normal incidence, the open void ratio, density and compressive strength. Since the sound absorbing behavior of a porous material is related to the size of the pores and the thickness of the specimen tested, the influence of the particle grain size of the ceramic waste and the thickness of the samples tested on the properties of the final product has been analyzed. The results obtained have been compared to a porous concrete made of crushed granite aggregate as a reference commercial material traditionally used in similar applications. Compositions with coarse particles showed greater sound absorption properties than compositions made with finer particles, besides presenting better sound absorption behavior than the reference porous concrete. Therefore, a ceramic waste-based porous concrete can be potentially recycled in the highway noise barriers field.El objetivo de este trabajo es desarrollar un material absorbente acústico compuesto fundamentalmente por residuos cerámicos (80% p) que se pueda utilizar en la fabricación de dispositivos reductores de ruido de carretera. La caracterización del producto se ha llevado a cabo atendiendo a sus propiedades acústicas, físicas y mecánicas, determinando el coeficiente de absorción acústica a incidencia normal, porosidad abierta, densidad y resistencia a compresión. La absorción acústica de un material poroso está fuertemente determinada por el tamaño de poro y por la longitud dela probeta sometida a ensayo. De este modo, se ha analizado la influencia del tamaño de partícula del residuo cerámico y del espesor de las muestras estudiadas en las propiedades del producto final. Los resultados obtenidos se han comparado con los obtenidos para un hormigón poroso elaborado con árido grueso, que se ha tomado como producto de referencia tradicionalmente empleado en este tipo de aplicaciones. Las composiciones elaboradas con el residuo de mayor tamaño de partícula han mostrado mayor absorción acústica, incluso mayor que las del hormigón poroso comercial. Por tanto, un hormigón poroso elaborado con residuos cerámicos puede ser potencialmente empleado como material en la fabricación de barreras acústicas de carretera

Phase behavior of the Confined Lebwohl-Lasher Model

The phase behavior of confined nematogens is studied using the Lebwohl-Lasher model. For three dimensional systems the model is known to exhibit a discontinuous nematic-isotropic phase transition, whereas the corresponding two dimensional systems apparently show a continuous Berezinskii-Kosterlitz-Thouless like transition. In this paper we study the phase transitions of the Lebwohl-Lasher model when confined between planar slits of different widths in order to establish the behavior of intermediate situations between the pure planar model and the three-dimensional system, and compare with previous estimates for the critical thickness, i.e. the slit width at which the transition switches from continuous to discontinuous.Comment: Submitted to Physical Review

Evaluation of the Psoriasis Transcriptome across Different Studies by Gene Set Enrichment Analysis (GSEA)

Our objective was to develop a consistent molecular definition of psoriasis. There have been several published microarray studies of psoriasis, and we compared disease-related genes identified across these different studies of psoriasis with our own in order to establish a consensus.We present a psoriasis transcriptome from a group of 15 patients enrolled in a clinical study, and assessed its biological validity using a set of important pathways known to be involved in psoriasis. We also identified a key set of cytokines that are now strongly implicated in driving disease-related pathology, but which are not detected well on gene array platforms and require more sensitive methods to measure mRNA levels in skin tissues. Comparison of our transcriptome with three other published lists of psoriasis genes showed apparent inconsistencies based on the number of overlapping genes. We extended the well-established approach of Gene Set Enrichment Analysis (GSEA) to compare a new study with these other published list of differentially expressed genes (DEG) in a more comprehensive manner. We applied our method to these three published psoriasis transcriptomes and found them to be in good agreement with our study.Due to wide variability in clinical protocols, platform and sample handling, and subtle disease-related signals, intersection of published DEG lists was unable to establish consensus between studies. In order to leverage the power of multiple transcriptomes reported by several laboratories using different patients and protocols, more sophisticated methods like the extension of GSEA presented here, should be used in order to overcome the shortcomings of overlapping individual DEG approach

Correlations in the low-temperature phase of the two-dimensional XY model

Monte Carlo simulations of the two-dimensional XY model are performed in a square geometry with fixed boundary conditions. Using a conformal mapping it is very easy to deduce the exponent eta_sigma(T) of the order parameter correlation function at any temperature in the critical phase of the model. The temperature behaviour of eta_sigma(T) is obtained numerically with a good accuracy up to the Kosterlitz-Thouless transition temperature. At very low temperatures, a good agreement is found with Berezinskii's harmonic approximation. Surprisingly, we show some evidence that there are no logarithmic corrections to the behaviour of the order parameter density profile (with symmetry breaking surface fields) at the Kosterlitz-Thouless transition temperature.Comment: 7 pages, 2 eps figure