Technical efficiency and spatial externalities: evidence from spanish small and middle-sized industrial firms

The aim of this paper is to analyze whether firms located inside a hypothetic cluster have a different performance in terms of technical efficiency from firms located outside. To undertake this analysis we present a methodology to overcome the restrictions suffered by this kind of studies, basically the radial efficiency measures. The methodological approach we propose is based on non-radial efficiency measures, also referred as the Russell measure. We present the main results obtained on a sample of small and middle-sized industrial firms located in the Valencian Community (Spain) to show the advantages of this methodology. Furthermore, we assess the links between the spatial location and some management characteristics at firm level.

Technical efficiency and spatial externalities: evidence from spanish small and middle-sized industrial firms

The aim of this paper is to analyze whether firms located inside a hypothetic cluster have a different performance in terms of technical efficiency from firms located outside. To undertake this analysis we present a methodology to overcome the restrictions suffered by this kind of studies, basically the radial efficiency measures. The methodological approach we propose is based on non-radial efficiency measures, also referred as the Russell measure. We present the main results obtained on a sample of small and middle-sized industrial firms located in the Valencian Community (Spain) to show the advantages of this methodology. Furthermore, we assess the links between the spatial location and some management characteristics at firm level

"In vino veritas": factores competitivos en distritos industriales productores de vino

El sector vitivinícola ocupa una destacada posición en el conjunto de la industria agroalimentaria española. La importancia demostrada por esta actividad se traslada también al mercado internacional donde España ostenta una posición de liderazgo tanto en términos de producción, como de ventas al exterior. Buena parte de las empresas elaboradoras de vino de nuestro país se ubican en distritos industriales, o lo que es lo mismo, en entornos geográficos caracterizados por la elevada concentración de pequeñas y medianas empresas cuya organización productiva responde a un esquema basado en la especialización flexible. En anteriores trabajos, se ha podido constatar cómo las empresas elaboradoras de vino ubicadas en este tipo de enclaves industriales presentan una mayor eficiencia respecto de competidores localizados en otro tipo de entornos. El objetivo de este artículo es profundizar en la investigación de los rasgos específicos de los distritos industriales que podrían explicar este plus de eficiencia de sus empresas. Para la identificación y cuantificación de estos factores determinantes de la eficiencia productiva se utiliza una metodología basada en modelos de ajuste paramétrico. Se lleva a cabo una aplicación empírica sobre una muestra de empresas españolas productoras de vino para los años 2000 y 2010, extraída de la base de datos SABI.The wine sector holds a prominent place within the whole Spanish food and agriculture industry. The importance given to this activity has also been transferred to the international market where Spain holds a position of leadership, both in terms of production as in overseas sales. A large number of the wine-producing firms in our country are located in industrial districts, which is to say in geographical areas characterised by a high concentration of small and medium-sized companies whose productive organisation corresponds to a model based on flexible specialisation. In previous papers, it has been possible to verify how wine-producing industries located in industrial areas show greater efficiency in relation to rivals located in other types of environments. The aim of this article is to further research on the specific features of industrial districts which could explain their firms’ increase in efficiency. For the identification and quantification of these determining factors affecting productive efficiency, a methodology based on parametric adjustments models is to be used. An empirical application is to be carried out on a sample of Spanish wine producers for the years 2000 and 2010, extracted from the SABI database

La Comunitat Valenciana y la política de cohesión como herramienta imprescindible de la construcción europea

El ISSN corresponde a la versión electrónica del documentoLos procesos de ampliación e integración actuales de la Unión Europea se enfrentan a un sinnúmero de obstáculos. Por ello, el sentimiento de pertenencia a Europa es el vínculo necesario entre aquellas personas y comunidades, como la comunidad y el pueblo valencianos, que comparten principios y valores que solo se han vuelto parte de nuestras vidas recorriendo un difícil camino y que, por ello mismo, se han construido sobre los cimientos europeos, ahora violentamente agitados por incontables desafíos

Integrative isotopic and molecular approach for the diagnosis and implementation of an efficient in-situ enhanced biological reductive dechlorination of chlorinated ethenes

Based on the previously observed intrinsic bioremediation potential of a site originally contaminated with perchloroethene (PCE), field-derived lactate-amended microcosms were performed to test different lactate isomers and concentrations, and find clearer isotopic and molecular parameters proving the feasibility of an in-situ enhanced reductive dechlorination (ERD) from PCE-to-ethene (ETH). According to these laboratory results, which confirmed the presence of Dehalococcoides sp. and the vcrA gene, an in-situ ERD pilot test consisting of a single injection of lactate in a monitoring well was performed and monitored for 190 days. The parameters used to follow the performance of the ERD comprised the analysis of i) hydrochemistry, including redox potential (Eh), and the concentrations of redox sensitive species, chlorinated ethenes (CEs), lactate, and acetate; ii) stable isotope composition of carbon of CEs, and sulphur and oxygen of sulphate; and iii) 16S rRNA gene sequencing from groundwater samples. Thus, it was proved that the injection of lactate promoted sulphate-reducing conditions, with the subsequent decrease in Eh, which allowed for the full reductive dechlorination of PCE to ETH in the injection well. The biodegradation of CEs was also confirmed by the enrichment in 13C and carbon isotopic mass balances. The metagenomic results evidenced the shift in the composition of the microbial population towards the predominance of fermentative bacteria. Given the success of the in-situ pilot test, a full-scale ERD with lactate was then implemented at the site. After one year of treatment, PCE and trichloroethene were mostly depleted, whereas vinyl chloride (VC) and ETH were the predominant metabolites. Most importantly, the shift of the carbon isotopic mass balances towards more positive values confirmed the complete reductive dechlorination, including the VC-to-ETH reaction step. The combination of techniques used here provides complementary lines of evidence for the diagnosis of the intrinsic biodegradation potential of a polluted site, but also to monitor the progress, identify potential difficulties, and evaluate the success of ERD at the field scale

Multi-method assessment of the intrinsic biodegradation potential of an aquifer contaminated with chlorinated ethenes at an industrial area in Barcelona (Spain)

The bioremediation potential of an aquifer contaminated with tetrachloroethene (PCE) was assessed by combining hydrogeochemical data of the site, microcosm studies, metabolites concentrations, compound specific-stable carbon isotope analysis and the identification of selected reductive dechlorination biomarker genes. The characterization of the site through 10 monitoring wells evidenced that leaked PCE was transformed to TCE and cis-DCE via hydrogenolysis. Carbon isotopic mass balance of chlorinated ethenes pointed to two distinct sources of contamination and discarded relevant alternate degradation pathways in the aquifer. Application of specific-genus primers targeting Dehalococcoides mccartyi species and the vinyl chloride-to-ethene reductive dehalogenase vcrA indicated the presence of autochthonous bacteria capable of the complete dechlorination of PCE. The observed cis-DCE stall was consistent with the aquifer geochemistry (positive redox potentials; presence of dissolved oxygen, nitrate, and sulphate; absence of ferrous iron), which was thermodynamically favourable to dechlorinate highly chlorinated ethenes but required lower redox potentials to evolve beyond cis-DCE to the innocuous end product ethene. Accordingly, the addition of lactate or a mixture of ethanol plus methanol as electron donor sources in parallel field-derived anoxic microcosms accelerated dechlorination of PCE and passed cis-DCE up to ethene, unlike the controls (without amendments, representative of field natural attenuation). Lactate fermentation produced acetate at near-stoichiometric amounts. The array of techniques used in this study provided complementary lines of evidence to suggest that enhanced anaerobic bioremediation using lactate as electron donor source is a feasible strategy to successfully decontaminate this site

Multi-method assessment of the intrinsic biodegradation potential of an aquifer contaminated with chlorinated ethenes at an industrial area in Barcelona (Spain)

The bioremediation potential of an aquifer contaminated with tetrachloroethene (PCE) was assessed by combining hydrogeochemical data of the site, microcosm studies, metabolites concentrations, compound specific-stable carbon isotope analysis and the identification of selected reductive dechlorination biomarker genes. The characterization of the site through 10 monitoring wells evidenced that leaked PCE was transformed to TCE and cis-DCE via hydrogenolysis. Carbon isotopic mass balance of chlorinated ethenes pointed to two distinct sources of contamination and discarded relevant alternate degradation pathways in the aquifer. Application of specific-genus primers targeting Dehalococcoides mccartyi species and the vinyl chloride-to-ethene reductive dehalogenase vcrA indicated the presence of autochthonous bacteria capable of the complete dechlorination of PCE. The observed cis-DCE stall was consistent with the aquifer geochemistry (positive redox potentials; presence of dissolved oxygen, nitrate, and sulphate; absence of ferrous iron), which was thermodynamically favourable to dechlorinate highly chlorinated ethenes but required lower redox potentials to evolve beyond cis-DCE to the innocuous end product ethene. Accordingly, the addition of lactate or a mixture of ethanol plus methanol as electron donor sources in parallel field-derived anoxic microcosms accelerated dechlorination of PCE and passed cis-DCE up to ethene, unlike the controls (without amendments, representative of field natural attenuation). Lactate fermentation produced acetate at near-stoichiometric amounts. The array of techniques used in this study provided complementary lines of evidence to suggest that enhanced anaerobic bioremediation using lactate as electron donor source is a feasible strategy to successfully decontaminate this site

Integrative isotopic and molecular approach for the diagnosis and implementation of an efficient in-situ enhanced biological reductive dechlorination of chlorinated ethenes

Based on the previously observed intrinsic bioremediation potential of a site originally contaminated with perchloroethene (PCE), field-derived lactate-amended microcosms were performed to test different lactate isomers and concentrations, and find clearer isotopic and molecular parameters proving the feasibility of an in-situ enhanced reductive dechlorination (ERD) from PCE-to-ethene (ETH). According to these laboratory results, which confirmed the presence of Dehalococcoides sp. and the vcrA gene, an in-situ ERD pilot test consisting of a single injection of lactate in a monitoring well was performed and monitored for 190 days. The parameters used to follow the performance of the ERD comprised the analysis of i) hydrochemistry, including redox potential (Eh), and the concentrations of redox sensitive species, chlorinated ethenes (CEs), lactate, and acetate; ii) stable isotope composition of carbon of CEs, and sulphur and oxygen of sulphate; and iii) 16S rRNA gene sequencing from groundwater samples. Thus, it was proved that the injection of lactate promoted sulphate-reducing conditions, with the subsequent decrease in Eh, which allowed for the full reductive dechlorination of PCE to ETH in the injection well. The biodegradation of CEs was also confirmed by the enrichment in 13C and carbon isotopic mass balances. The metagenomic results evidenced the shift in the composition of the microbial population towards the predominance of fermentative bacteria. Given the success of the in-situ pilot test, a full-scale ERD with lactate was then implemented at the site. After one year of treatment, PCE and trichloroethene were mostly depleted, whereas vinyl chloride (VC) and ETH were the predominant metabolites. Most importantly, the shift of the carbon isotopic mass balances towards more positive values confirmed the complete reductive dechlorination, including the VC-to-ETH reaction step. The combination of techniques used here provides complementary lines of evidence for the diagnosis of the intrinsic biodegradation potential of a polluted site, but also to monitor the progress, identify potential difficulties, and evaluate the success of ERD at the field scale

Use of dual element isotope analysis and microcosm studies to determine the origin and potential anaerobic biodegradation of dichloromethane in two multi-contaminated aquifers

Many aquifers around the world are impacted by toxic chlorinated methanes derived from industrial processes due to accidental spills. Frequently, these contaminants co-occur with chlorinated ethenes and/or chlorinated benzenes in groundwater, forming complex mixtures that become very difficult to remediate. In this study, a multi-method approach was used to provide lines of evidence of natural attenuation processes and potential setbacks in the implementation of bioremediation strategies in multi-contaminated aquifers. First, this study determined i) the carbon and chlorine isotopic compositions (δ¹³C, δ³⁷Cl) of several commercial pure phase chlorinated compounds, and ii) the chlorine isotopic fractionation (εCl = −5.2 ± 0.6‰) and the dual CCl isotope correlation (ΛC/Cl = 5.9 ± 0.3) during dichloromethane (DCM) degradation by a Dehalobacterium-containing culture. Such data provide valuable information for practitioners to support the interpretation of stable isotope analyses derived from polluted sites. Second, the bioremediation potential of two industrial sites contaminated with a mixture of organic pollutants (mainly DCM, chloroform (CF), trichloroethene (TCE), and mono-chlorobenzene (MCB)) was evaluated. Hydrochemistry, dual (CCl) isotope analyses, laboratory microcosms, and microbiological data were used to investigate the origin, fate and biodegradation potential of chlorinated methanes. At Site 1, δ¹³C and δ³⁷Cl compositions from field samples were consistent with laboratory microcosms, which showed complete degradation of CF, DCM and TCE, while MCB remained. Identification of Dehalobacter sp. in CF-enriched microcosms further supported the biodegradation capability of the aquifer to remediate chlorinated methanes. At Site 2, hydrochemistry and δ¹³C and δ³⁷Cl compositions from field samples suggested little DCM, CF and TCE transformation; however, laboratory microcosms evidenced that their degradation was severely inhibited, probably by co-contamination. A dual CCl isotopic assessment using results from this study and reference values from the literature allowed to determine the extent of degradation and elucidated the origin of chlorinated methanes