Petrol consumption and redistributive effects of its taxation in Spain

The objective of this paper is to estimate a petrol consumption function for Spain and to evaluate the redistributive effects of petrol taxation. We use micro data from the Spanish Household Budget Survey of 1990/91 and model petrol consumption taking into account the effect that income changes may have on car ownership levels, as well as the differences that exist between expenditure and consumption. Our results show the importance that household structure, place of residence and income have on petrol consumption. We are able to compute income elasticities of petrol expenditure, both conditional and unconditional on the level of car ownership. Non-conditional elasticities, while always very close to unit values, are lower for higher income households and for those living in rural areas or small cities. When car ownership levels are taken into account, conditional elasticities are obtained that are around one half the value of the non- conditional ones, being fairly stable across income categories and city sizes. As regards the redistributive effects of petrol taxation, we observe that for the lowest income deciles the share of petrol expenditure increases with income, and thus the tax can be regarded as progressive. However, after a certain income level the tax proves to be regressive.

Capital humano y desigualdad en España: 1985-1996

En el período 1985-1996 la desigualdad de la renta en España se redujo de forma notable, en claro contraste con lo sucedido en otros países avanzados. En este trabajo se profundiza en el impacto que sobre esta reducción en la desigualdad ha ejercido la redistribución del stock de capital humano, uno de los factores que aparecen como más relevantes para explicar tanto la distribución de la renta como sus modificaciones. Las conclusiones obtenidas sugieren que aproximadamente un tercio de la reducción en la desigualdad que se ha producido entre los dos años extremos contemplados (1985 frente a 1996) se debe al comportamiento del capital humano. Otros factores tales como el tamaño de la familia o la participación de ambos cónyuges en el mercado de trabajo, han actuado en el mismo sentido. Finalmente, un elevado porcentaje de mejora en la distribución permanece por explicar y deberá ser objeto de investigaciones futuras.

Necesidad de formación en el mercado de trabajo español: composición del empleo y estructura productiva

Este trabajo estudia las intensas transformaciones que se han producido en la composición del empleo español por niveles de educación y por categoría profesional. Mediante una técnica de descomposición “shift-share” se desagregan los efectos inputados al cambio técnico sesgado y al cambio técnico desigual, y se advierte que, en la segunda mitad de los noventa, se ha producido una ruptura con la pauta de comportamiento anterior. En efecto, a partir de 1995, el incremento de participación total del empleo cualificado ha venido determinado con mucha mayor intensidad que en períodos anteriores por el cambio técnico sesgado. Cuando, en cambio, esta influencia se examina desde la perspectiva de la recomposición del empleo por categoría profesional se observa que ha sido mucho menor. Ello permite introducir, aunque de manera muy preliminar, la hipótesis de sobreeducación en el mercado de trabajo español, que según los resultados obtenidos y como es de esperar, sólo afectaría a los colectivos más formados con relación a las categorías profesionales con empleos no manuales.

The demand elasticity on tolled motorways

This paper analyses the elasticities of demand in tolled motorways in Spain with respect to the main variables influencing it. The demand equation is estimated using a panel data set where the cross-section observations correspond to the different Spanish tolled motorways sections, and the temporal dimension ranges from the beginning of the eighties until the end of the nineties. The results show a high elasticity with respect to the economic activity level. The average elasticity with respect to petrol price falls around -0.3, while toll elasticities clearly vary across motorway sections. These motorway sections are classified into four groups according to the estimated toll elasticity with values that range from -0.21 for the most inelastic to -0.83 for the most elastic. The main factors that explain such differences are the quality of the alternative road and the length of the section. The long-term effect is about 50 per cent higher than the short term one; however, the period of adjustment is relatively short.

The short and long-run determinants of the real exchange rate in Mexico

This paper explores the real exchange rate behavior in Mexico from 1960 until 2005. Since the empirical analysis reveals that the real exchange rate is not mean reverting, we propose that economic fundamental variables affect its evolution in the long-run. Therefore, based on equilibrium exchange rate paradigms, we propose a simple model of real exchange rate determination which includes the relative labor productivity, the real interest rates and the net foreign assets over a long period of time. Our analysis also considers the dynamic adjustment in response to shocks through impulse response functions derived from the multivariate VAR model.

Immunological aspects of host-schistosome relationships

The complex immunological relationships between schistosomes and their vertebrate hosts are considered to be conveniently divisible into four distinct, though interrelated categories: the parasite's vulnerability to, its evasion of, and its exploitation of the host's immune response, and its stimulation of the host's immune response to produce immunopathology. Some significant recent advances in the first three categories are discussed, as well as their relationships to the fourth category of immunopathology.

Job accessibility and employment probability

The objective of this paper is to estimate the impact of residential job accessibility on female employment probability in the metropolitan areas of Barcelona and Madrid. Following a “spatial mismatch” framework, we estimate a female employment probability equation where variables controlling for personal characteristics, residential segregation and employment potential on public transport network are included. Data used come from Microcensus 2001 of INE (National Institute of Statistics). The research focuses on the treatment of endogeneity problems and the measurement of accessibility variables. Our results show that low job accessibility in public transport negatively affects employment probability. The intensity of this effect tends to decrease with individual’s educational attainment. A higher degree of residential segregation also reduces job probability in a significant way..

Car ownership and access to jobs in Spain

This study analyses the impact that job accessibility in public transport has on car ownership. An ordered probit explaining the number of cars per household is estimated as a function of head of household characteristics, household characteristics and job accessibility. The data used in the analysis come from the Microcensus of year 2001 of the Spanish Institute of Statistics for the areas of Barcelona and Madrid. Our results show a significant effect of accessibility on car ownership. Additionally, we carried out simulation exercises in which the expected number of vehicles decreases as accessibility improves. For instance, in the case of households living outside the central city, an improvement of accessibility up to the average level of the central city would offset the effect of the number of working adults on the expected number of vehicles.

Safety and occlusion rates of surgical treatment of unruptured intracranial aneurysms: a systematic review and meta-analysis of the literature from 1990 to 2011.

BACKGROUND AND PURPOSE: Surgical clipping of unruptured intracranial aneurysms (UIAs) has recently been challenged by the emergence of endovascular treatment. We performed an updated systematic review and meta-analysis on the surgical treatment of UIAs, in an attempt to determine the aneurysm occlusion rates and safety of surgery in the modern era. METHODS: A detailed protocol was developed prior to conducting the review according to the Cochrane Collaboration guidelines. Electronic databases spanning January 1990-April 2011 were searched, complemented by hand searching. Heterogeneity was assessed using I(2), and publication bias with funnel plots. Surgical mortality and morbidity were analysed with weighted random effect models. RESULTS: 60 studies with 9845 patients harbouring 10 845 aneurysms were included. Mortality occurred in 157 patients (1.7%; 99% CI 0.9% to 3.0%; I(2)=82%). Unfavourable outcomes, including death, occurred in 692 patients (6.7%; 99% CI 4.9% to 9.0%; I(2)=85%). Morbidity rates were significantly greater in higher quality studies, and with large or posterior circulation aneurysms. Reported morbidity rates decreased over time. Studies were generally of poor quality; funnel plots showed heterogeneous results and publication bias, and data on aneurysm occlusion rates were scant. CONCLUSIONS: In studies published between 1990 and 2011, clipping of UIAs was associated with 1.7% mortality and 6.7% overall morbidity. The reputed durability of clipping has not been rigorously documented. Due to the quality of the included studies, the available literature cannot properly guide clinical decisions.

Cross-section data, disequilibrium situations and estimated coefficients: evidence from car ownership demand

The objective of this paper is to analyse to what extent the use of cross-section data will distort the estimated elasticities for car ownership demand when the observed variables do not correspond to a state equilibrium for some individuals in the sample. Our proposal consists of approximating the equilibrium values of the observed variables by constructing a pseudo-panel data set which entails averaging individuals observed at different points of time into cohorts. The results show that individual and aggregate data lead to almost the same value for income elasticity, whereas with respect to working adult elasticity the similarity is less pronounced.

Una propuesta de evaluación de las externalidades de capital humano en la empresa

Empleando la encuesta de estructura salarial se plantea una propuesta de estimación de externalidades de capital humano intraempresa que permite relajar las restricciones introducidas por las especificaciones que la literatura empírica existente ha usado. En concreto, la metodología propuesta evalúa las externalidades de capital humano aprovechando al máximo la variabilidad en la muestra, al permitir que todos los coeficientes de las ecuaciones estimadas varíen con el nivel de capital humano del establecimiento, relajando la hipótesis implícita de linealidad entre el efecto de externalidad y el nivel educativo de los individuos.

Capital humano: un análisis comparativo Catalunya-España

En este documento se analizan comparativamente algunos aspectos relativos al capital humano de la economía catalana y española. En primer lugar se compara la dotación de capital humano tanto desde una metodología más tradicional, como es el caso de años de educación, como desde el punto de vista de la valoración del activo mediante actualización de flujos salariales a lo largo del ciclo vital de los individuos. Los resultados muestran indicios de una cierta desaceleración en el crecimiento del stock de capital humano. Adicionalmente, se lleva a cabo una estimación de la existencia de externalidades de capital humano intra-establecimiento, con datos de la Encuesta de Estructura Salarial, desarrollando una metodología menos restrictiva que la tradicional. Los resultados muestran comportamientos similares de la economía española y catalana, apuntando a la existencia de externalidades.

Economic development and changes in car ownership patterns

The contributions of this paper are twofold: On the one hand, the paper analyses the factors determining the growth in car ownership in Spain over the last two decades, and, on the other, the paper provides empirical evidence for a controversial methodological issue. From a methodological point of view, the paper compares the two alternative decision mechanisms used for modelling car ownership: ordered-response versus unordered-response mechanisms. A discrete choice model is estimated at three points in time: 1980, 1990 and 2000. The study concludes that on the basis of forecasting performance, the multinomial logit model and the ordered probit model are almost undistinguishable. As for the empirical results, it can be emphasised that income elasticity is not constant and declines as car ownership increases. Besides, households living in rural areas are less sensitive than those living in urban areas. Car ownership is also sensitive to the quality of public transport for those living in the largest cities. The results also confirmed the existence of a generation effect, which will vanish around the year 2020, a weak life-cycle effect, and a positive effect of employment on the number of cars per household. Finally, the change in the estimated coefficients over time reflects an increase in mobility needs and, consequently, an increase in car ownership.

Traffic forecasts under uncertainty and capacity constraints

Traffic forecasts provide essential input for the appraisal of transport investment projects. However, according to recent empirical evidence, long-term predictions are subject to high levels of uncertainty. This paper quantifies uncertainty in traffic forecasts for the tolled motorway network in Spain. Uncertainty is quantified in the form of a confidence interval for the traffic forecast that includes both model uncertainty and input uncertainty. We apply a stochastic simulation process based on bootstrapping techniques. Furthermore, the paper proposes a new methodology to account for capacity constraints in long-term traffic forecasts. Specifically, we suggest a dynamic model in which the speed of adjustment is related to the ratio between the actual traffic flow and the maximum capacity of the motorway. This methodology is applied to a specific public policy that consists of suppressing the toll on a certain motorway section before the concession expires.