El teorema de Okishio en ciertos tipos de economías convexas

The Okishio's theorem has been just studied in Leontief and von Neumann's models (see Okishio (1961) and Roemer (1980 and 1981). This article extend it for a more general economy with convex production sets and limited initial endowments. Firstly, that I define the economic model and its possible equilibria, then I proof there exist always solutions in two of them, named quasi reproducible solutions and quasi competitive solutions. Another important issue is to know which is the impact of the capitalist's number in the theorem, I proof when it's not important and I show a solution for resting cases. Besides l extend the Okishio's theorem for warranted rates of profit and quasi reproducible soIutions and I get a relation between warranted rates under quasi reproducible solutions and quasi competitive solutions.El teorema de Okishio ha sido estudiado hasta hoy en economías Leontief y von Neumann (Okishio (1961) y Roemer (1980 y 1981). Ahora queremos generalizarlo para algunas economías convexas más amplias y que tienen limitaciones en las dotaciones iniciales. Primeramente definimos el modelo económico y sus tipos de equilibrio y vemos que para dos de ellos existe siempre solución, son las llamadas soluciones casi reproducibles y las soluciones casi competitivas. A continuación revisamos la influencia del número de capitalistas en el teorema, viendo cuando esta cuestión es indiferente y proponiendo una solución para los demás casos. Después demostramos una extensión del teorema para tasas garantizadas y soluciones casi reproducibles, viendo para finalizar la relación entre las tasas garantizadas de las soluciones casi reproducibles y de las casi competitivas

Irrigation water management: An analysis using computable general equilibrium models

La Tesis Doctoral aborda la gestión del agua de regadío mediante la utilización de modelos de equilibrio general aplicado. Este trabajo está divido en tres partes. La primera parte se compone de un capítulo descriptivo que analiza la situación hídrica del Alto Aragón durante la primera década del siglo XXI, así como las características principales de su gestión y uso del agua, estimando usos, niveles de eficiencia, rentabilidades, consumos efectivos, etc. La segunda parte presenta un capítulo con componente teórico que presenta la metodología que se va a trabajar en la Tesis. Se desarrollan tres modelos de equilibrio general aplicado que permiten analizar escenarios de cambio para la gestión del agua en el regadío. Estos modelos se caracterizan por ser una de las principales herramientas actuales en la toma de decisiones de política económica y medioambiental. La tercera parte de la tesis plantea tres aplicaciones empíricas. El tercer capítulo analiza los efectos de una mayor responsabilidad social en el uso del agua en el regadío a través de un modelo estático. El cuarto capítulo de contenido empírico profundiza en diversas estrategias para abordar futuros cambios en la disponibilidad hídrica. Se evalúan cuatro tipos de cambio tecnológico en la agricultura y se tiene en cuenta el marco institucional analizando medidas de políticas de precios de agua en línea con la Directiva Marco del Agua. Finalmente, el último capítulo de la tesis incorpora la incertidumbre en la disponibilidad de recursos y en el cambio tecnológico para valorar los resultados obtenidos del capítulo cuarto. Los resultados de la Tesis son de inmediata aplicación para los agentes interesados (regantes, principalmente), agentes decisores y la sociedad en su conjunto, mostrando que los modelos de equilibrio general aplicado son una herramienta útil para la gestión del agua de regadío y la recomendación de políticas económicas y medioambientales, pero siempre que sean diseñados de acuerdo a las características de la región de estudio y a los objetivos que se plantean

Downscaling the grey water footprints of production and consumption

While economic and environmental policies and strategies are largely designed at the international, national or regional level, the environmental impacts of these measures are often felt at a more geographically-localized level. In particular, the effects on water resources, especially regarding water pollution and water stress, are usually localized in very specific hotspots. In this work, we acknowledge these facts and attempt to identify the linkages among the 17 regions in Spain (a semi-arid country with significant geographical variations in water availability), the European Union (EU), and the Rest of the World (RW), while also looking at the local effects of those interactions. In particular, we study the grey water footprints (a measure of the assimilation capacity of water resources) of production, at both the regional and business level, with spatially explicit information, and the extension of those footprints throughout the supply chain, while also computing the water footprints of consumption at the regional level. This process is a combination of a detailed computation of grey water footprints from production, from agriculture (from diffuse pollution), and from more general economic activities (from point source pollution), with a multiregional input–output model that encompasses the 17 Spanish Regions, the EU, and the RW. We also identify hotspots and vulnerable areas, linking the grey water footprints from production originating in these areas to final-consumer responsibilities. As an example of the potential of the combined methodology, we design and evaluate the effects on grey water footprints of scenarios of import substitutions in Spain. Our results show strong final demand in regions such as Madrid and Catalonia, and in net exporting regions such as Andalusia, Aragon, Castile and Leon, Castile-La Mancha, Extremadura, and Navarre. Some of these regions contain areas that are clearly vulnerable to nitrates and other pollutants, and parts of these regions, most obviously in Andalusia and Extremadura, suffer water stress, which leads us to question the sustainability of the relationships between the structure of production and trade and the environment

Análisis de los recursos hídricos de Riegos del Alto Aragón (Huesca) en la primera década del siglo XXI

[EN] This paper aims to analyze the evolution in recent years of the water situation in Riegos del Alto Aragón (127.210 ha), a major irrigation scheme in north-eastern Spain. We study the evolution of water demand, irrigation efficiency, cropping patterns and crop profitability for the whole irrigationarea and for each of its 58 community members. We have obtained significant figures in the current levels of irrigation efficiency and they are of immediate application for the improvement of water management policy. On the one hand, the findings show the need to stop the current expansion of irrigation in this community, and on the other hand, they indicate that water scarcity is now provoking shocking changes in the cropping pattern removing towards less water demanding crops and with lower profitability, instead of the expected evolution (more weight of fruits, vegetables, corn,...)[ES] Este trabajo profundiza en la evolución de la situación hídrica de la Comunidad General de Riegos del Alto Aragón (127.210 ha), localizada en el noreste español. Se analiza para el conjunto de esta zona regable y para cada una de sus 58 comunidades de regantes la evolución de las demandas de agua, los niveles de eficiencia, los patrones de cultivos y su rentabilidad económica. Las cifras obtenidas de los niveles de eficiencia son muy significativas y de aplicación inmediata para la mejora de la política de gestión del agua. Los resultados muestran por una parte la necesidad de detener la actual expansión del regadío en esta comunidad, y por otra que la falta de agua está provocando cambios en los patrones de cultivo hacia cultivos menos exigentes de agua y con menor rentabilidad económica, en lugar de lo esperado (más frutales, hortalizas, maíz,…).El presente trabajo ha sido financiado por el proyecto OTRI-2011/0155 financiado por la Comunidad General de Riegos del Alto Aragón y también por la beca FPU AP2010-3729. Los autores agradecen a los evaluadores anónimos de EARN por sus útiles comentarios.Sánchez-Chóliz, J.; Sarasa, C. (2013). Water resources analysis in Riegos del Alto Aragón (Huesca) in the first decade of the 21st Century. Economía Agraria y Recursos Naturales - Agricultural and Resource Economics. 13(1):97-124. https://doi.org/10.7201/earn.2013.01.05SWORD9712413

Water and production reallocation in the Spanish agri-food system

Multiregional input–output (MRIO) and computable general equilibrium (CGE) models have greatly facilitated approaches to environmental and economic problems in recent years. This paper examines regional reallocation criteria intended to reduce water constraints in the Spanish economy. Our goal is to assess the impact of alternative allocation scenarios for regional production on the country’s agriculture and agri-food industries, and the associated effects on water resources along the whole length of food supply chains, which display significant asymmetries between regions caused by imbalances in the availability of water resources. We design a CGE model using an MRIO database for Spain. Our scenarios are based on increases in the production of water-intensive crops in regions with more abundant water resources and the development of more sustainable food supply chains between farms and the agri-food industry. Our findings point to a series of policy options that could be applied to ensure successful outcomes in both directions

Innovación tecnológica en el marco input-output. Una aplicación al caso español

En este trabajo se pretende mostrar cómo se puede obtener información sobre la innovación tecnológica de los sectores a través de las tablas input-output. Para ello primero se hace un análisis analítico de este instrumento y posteriormente se realiza una aplicación al caso español entre los años 1980-2007, utilizando el análisis de descomposición estructural

Análisis de los últimos cambios en el sector eólico

En el presente documento, se realiza un análisis del impacto de los diferentes cambios y nuevas regulaciones que surgen en el sector eólico tanto de ingresos como en la rentabilidad, además de una descripción de la evolución del marco normativo del sector eólico en España

The geographical and sectoral concentration of global supply chains

Due to international fragmentation, production increasingly occurs in global supply chains (GSC). The common belief is that this leads to more specialization, which implies more concentration of imports and exports over time. In this paper, we empirically test this hypothesis by analysing the geographical and sectoral concentration of GSC over the period 1995–2011. We adapt the traditional Herfindahl’s concentration indexes to a multi-regional input–output framework. Taking the information on intersectoral and interregional linkages into full account gives the concentration indexes of GSC. The indexes are at different aggregation levels, which enables us to examine both geographical and sectoral concentration patterns. After that, we analyse the effect a country’s geographical and sectoral concentration on its gross domestic product (GDP) per capita. Our findings are: an increase of geographical and sectoral concentration of GSC from 1995 to 2011; a growing role in global production chains played by China and other Asian countries; less concentration for European Union countries; a significant positive effect of geographical concentration on GDP per capita; and a significant negative effect of sectoral concentration

New insights on the relationship between the involvement of countries in global value chains, and intra- and inter-country inequalities

Recent economic growth cannot be understood without considering the emergence of Global Value Chains (GVCs). However, recent literature has highlighted that economic upgrading cannot be taken as a granted result of the involvement in GVCs, and it does not necessarily lead to positive social outcomes. We explore whether the recent performance of countries in the GVCs has significantly conditioned the intra- and inter-country inequalities. Using a combined multisectoral-multiregional (MRIO) and econometric approach, we analyze 67 countries during 1995–2018. Regarding involvement in GVCs, we look into “smile curves”, in reference to the quadratic relation between position and inequality. The results show different geographical patterns. For intra-country inequality, we find significant “smile curves” in Developed, African, Latin American, and Asian countries, so these can reduce internal inequalities by moving to intermediate positions in GVCs. For inter-country inequality, results suggest opportunities for catching-up in Latin America and Africa by specializing in the tails