A Cointegration Analysis of the Long-Run Supply Response of Spanish Agriculture to the Common Agricultural Policy

Using cointegration techniques, we estimate two models that capture the long-term relationship between Spanish prices and agricultural production. The models were estimated over Spanish agricultural data from 1970 to 2000, a period spanning Spain’s implementation of the Common Agricultural Policy in 1986 and the application of the MacSharry Reforms in 1992. The models, as well asplausible counterfactual scenarios constructed to assess the production changes induced by the CAP, lead to three principal results. First, we find that Spanish agricultural output is responsive to agricultural prices. Second, we find that the MacSharry reforms have been instrumental in restraining agricultural production. Third, we find that Spanish agricultural output would have been higher if Spain had not applied the CAP. These results are important and have broad implications. First, they strengthen the position of those reformers both within and outside of Europe that argue for lower price supports as an appropriate policy for stemming European agricultural surpluses. Second, they indicate that recent EU reforms, which have in effect extended the MacSharry reforms, are appropriate measures for curbing European agricultural surpluses

Two-ballot versus plurality rule: an empirical investigation on the number of candidates

Duverger claimed more than 50 years ago that the number of candidates in elections should be a function of electoral rules. Both his “law” and “hypothesis” suggest the number of candidates vying for seats in elections to be tightly linked to characteristics of the electoral process such as its degree of proportionality and the presence of runoffs. Here we test the validity of Duverger’s claim using data from municipal elections in Brazil. Our study differs from others in the field in two important dimensions. First, by using municipal data we avoid the usual problems that plague statistical analysis using cross-country data. Secondly, we have a truly exogenous source of variation due to a change in electoral legislation introduced by the constitutional reform of 1988: simple plurality remained the rule only in municipalities with less than 200,000 voters, and a second-ballot became mandatory for the others above that threshold. This allows for a neat identification strategy using panel data. Our main finding is that elections with runoffs lure greater numbers of candidates in municipalities with sufficiently high levels of heterogeneity.Duverger's law, runoff, heterogeneity

Persistence in Airline Accidents

This paper analyses airline accident data from 1927-2006, through fractional integration. It is shown that airline accidents are persistent and (fractionally) cointegrated with airline traffic. There exists a negative relation between air accidents and airline traffic, with the effect of the shocks to that relationship disappearing in the long run. Policy implications are derived for countering accident events.Accidents; airline; Time series; Persistence; Long memory; Cointegration.

Registro de información en motores de automóviles y desarrollo de un ciclo de conducción piloto para la ciudad de Pereira usando herramientas de diagnóstico de bajo costo

(Eng) The objective of this paper is to present a methodology designed to develop a driving cycle to model traffic in the Pereira city in Colombia. Under the scope of this pilot work, four different gasoline passenger cars furnished with real time datalogging equipment were used to collect speed-time data under actual traffic along Pereira urban area. The speed-acceleration characteristics were analyzed, and target driving parameters were defined and evaluated. The designed method for building the driving cycle was then applied. As a result, a simple driving schedule for analyzing propulsion, fuel consumption rate, and emission control strategies of automobiles under Pereira downtown conditions has been proposed. Under the scope of the same project, was also studied the utility of the engine specific data collected during the vehicle operation for the purposes of engine performance assessment.(Spa) El objetivo de este trabajo es presentar una metodología para la obtención de un ciclo de conducción representativo del tráfico en la ciudad de Pereira, Colombia, usando herramientas de bajo costo. Se escogieron cuatro vehículos equipados con sistemas de registro de velocidad y aceleración para circular en uno de los corredores viales más congestionados de la ciudad. Las características de velocidad y aceleración fueron analizadas y se evaluaron y definieron los parámetros de conducción. Se diseñó un método para construir el ciclo de conducción y se construyó el ciclo. Como resultado, se obtuvo un ciclo simple de conducción que puede servir de referencia para el análisis de consumo de combustible y diseño de estrategias para control de emisiones de automóviles bajo las condiciones de operación en la zona urbana de Pereira. En el ámbito del mismo proyecto, también se estudió la utilidad de la información recolectada, con herramientas de diagnóstico de bajo costo, durante la operación de los vehículos para propósitos de evaluación del desempeño de los motores

Terrestrial mammal responses to habitat structure and quality of remnant riparian forests in an Amazonian cattle-ranching landscape

Extensive 1970–2010 deforestation in the Brazilian Amazon has generated a ~ 1.5 Mha fragmented region known as the ‘arc of deforestation’. Farmers and cattle ranchers throughout Brazil are legally required to set-aside riparian forest strips within their landholdings, but recent legislative changes have relaxed the minimum mandatory conditions of these riparian forests. In this context, we assessed the functional role of riparian forest remnants as landscape connectors for medium to large-bodied terrestrial mammals in a vast fragmented landscape of southern Amazonia. We selected 38 riparian forest strips and five riparian sites within continuous forest, installed four to five camera-traps along each riparian zone (199 camera-trap stations), and sampled the terrestrial mammal assemblage for 60 days per station during the dry seasons of 2013 and 2014. We compared mammal use of riparian forests within both continuous and highly fragmented forests, and examined the effects of corridor width, corridor habitat structure, and landscape context on mammal species richness, composition, and functional diversity, all of which were higher in continuous forests than in riparian remnants. Functional diversity differences between corridor type was trait-independent and mediated by differences in species richness. Forest habitat degradation was associated with overall lower species richness, whereas forest specialists were more species-rich in increasingly wider corridors. Compositional shifts indicate that deforestation and forest degradation favours matrix-tolerant species with lower levels of forest habitat specificity. We show the potential landscape connectivity role for forest mammals of riparian corridors, whose width and forest degradation status are key predictors of community-wide responses. We provide evidence on the importance of these relict riparian strips to forest vertebrates, strengthening the scientific arguments that help justify the recently embattled legal requirements to maintain effective riparian corridors in Brazil

Operación integrada de redes de distribución de energía y gas natural: un análisis de confiabilidad

Currently the world faces a great challenge, to achieve a sustainable production of energy, which allows the adequate development of humanity but at the same time does not irreversibly affect the environment. For this, it is absolutely necessary to make optimal and effective use of the available energy resources, in order to aim for energy transition objectives that result in the rational and efficient use of energy, the penetration of renewable resources, and social development. This requires that at a technical level, methodologies be proposed that allow for a holistic analysis of the different interactions and synergies present in the energy system. Therefore, it is essential to delve into the knowledge associated with the interaction between the electricity and natural gas networks, since natural gas is expected to be the energy source that supports the increase in generation from intermittent renewable energy sources. It is for the above that this research work analyzes the reliability of the electric power distribution network based on the impact associated with a contingency in the natural gas distribution network, when both networks are coupled through natural gas-based distributed power generators. A novel non-supplied energy index and a single contingency criterion are used for estimation purposes, considering failure rates and repair times of the natural gas network to obtain a more accurate in the estimation. Numerical results show that significant penetration of natural gas-based distributed generation can compromise the reliability of the power distribution network if the natural gas network is of low reliability.Actualmente, el mundo enfrenta un gran desafío y es lograr una producción sustentable de energía que permita el adecuado desarrollo de la humanidad pero que al mismo tiempo no afecte irreversiblemente al medio ambiente. Para ello, es absolutamente necesario hacer un uso óptimo y efectivo de los recursos energéticos disponibles, con el fin de apuntar a objetivos de una transición energética que resulten en un uso racional y eficiente de la energía, la penetración de los recursos renovables y el desarrollo social. Esto requiere que a nivel técnico se propongan metodologías que permitan un análisis holístico de las diferentes interacciones y sinergias presentes en el sistema energético. Por ello, es fundamental profundizar en el conocimiento asociado a la interacción entre las redes de electricidad y gas natural, ya que se espera que el gas natural sea la fuente energética que sustente el incremento de la generación a partir de fuentes renovables intermitentes. Por lo anterior, en este trabajo de investigación se analiza la confiabilidad de la red de distribución de energía eléctrica a partir del impacto asociado a una contingencia en la red de distribución de gas natural, cuando ambas redes se acoplan a través de generadores de energía distribuida a base de gas natural. Para su estimación se utiliza un novedoso índice de energía no suministrada y un criterio de contingencia sencilla, considerando tasas de falla y tiempos de reparación de la red de gas natural para obtener una mayor precisión en la estimación. Los resultados numéricos muestran que una penetración significativa de la generación distribuida basada en gas natural puede comprometer la confiabilidad de la red de distribución de energía si la red de gas natural es de baja confiabilidad