Over the last decades a transition from a state-own monopoly to a private business took place in the Spanish fuel sector. To figure out whether downstream prices react differently to upstream price increases than to price decreases, alternative dynamic nonlinear and asymmetric error correction models are applied to weekly price data. This paper analyse the existence of price asymmetries in the fuel market in Spain during the 2011-2016 period. In comparison with traditional asymmetric price theory literature, this paper introduces a new double threshold error correction (ECM) model (DT-ECM) and new double logistic ECM models and compares them with more common linear ECM, time varying parameter models (TV-ECM), threshold autoregressive models (T-ECM), smooth transition autoregressive (STAR) models and nonlinear error correction (Logistic-ECM) and double threshold Logistic (DT-Logistic ECM). The nonlinear and asymmetric results found show that sophisticated bivariate long-run asymmetries are present in the prices of the fuel sector and that those price reactions depend on whether the oil price increases or decreases, on the stage of the production, the distribution chain as well as on the period considered.JEL classification: B23, C24, C52, D43, L13, L71.

The ratio between the amount of mortgage loans and the value of housing (the loan to value ratio) is a useful indicator for studying the financial situation of households. Two main price indicators are used to measure loan to value ratios for housing in Spain at the time of purchase: the transaction price recorded at the Property Registry and the appraisal value. Having generated a sample in which both price indicators refer to the same set of housing, the median loan to value ratio between 2004 and 2007 is found to stand between 70%, when the appraisal value is used, and 107%, when the transaction price is used.The difference between these two ratios narrowed from 2010, with the loan to value ratio using the appraisal value remaining at around 70%, while the ratio based on the transaction value fell to 80%. The Spanish Survey of Household Finances (EFF), conducted by the Banco de España, is an alternative data source, allowing a loan to value ratio to be obtained directly from households' responses. This ratio, based on EFF data, has evolved in a similar way to the one derived from the transaction prices recorded at the Property Registry.

Resumen: Se utiliza la Teoría de la Difusión de la Innovación como marco conceptual adecuado desde la perspectiva sociológica para investigar el usuario como elemento fundamental en la planificación de servicios de información. A partir de la aplicación de este modelo teórico, se segmentan los investigadores de la Universidad de Extremadura atendiendo a las cinco categorías propuestas por Rogers, y se analizan los factores positivos y negativos que afectan a la adopción de recursos electrónicos como innovación, en función de la percepción de las características de ésta por los usuarios y del marco institucional en el que se produce. De acuerdo a los resultados obtenidos, se detecta la importancia del bibliotecario-documentalista como agente de cambio y la necesidad de la puesta en marcha de un Plan de formación de usuarios como estrategia de difusión de estos recursos en el marco de la organización, adaptado a las necesidades específicas de las distintas categorías y a los factores que influyen en su adopción, relacionados con el conocimiento, las habilidades de uso o los canales de comunicación. Palabras clave: planificación de servicios de información, estudio de usuarios, evaluación de recursos electrónicos, formación de usuarios, Teoría de la Difusión de la Innovación, Universidad de Extremadura.Abstract: Diffusion of Innovations Theory is used as an appropriate conceptual frame from a sociological perspective to investigate the user like fundamental element in information services planning. From the application of this theoretical model, Extremadura University's researchers are divided into the five categories proposed by Rogers. Moreover, some positive and negative factors are analysed to determine how they affect the adoption of electronic resources (innovation), studying the perception of the users within their institutional frame. According to our present results, it is detected how important the information professionals are, because they act as a change agent. In addition, we claim the necessity of an users formation plan like strategy of diffusion of these resources in the organization framework, adapted to specific necessities of the different categories and factors that influence their adoption, related to the knowledge, skills, or communication channels.

The main objective of this paper is to analyse the different sources of asymmetric price transmissions in the fuel market for France, Germany and Spain. During the last decades, the EU has carried out several common energy policies to achieve more efficient and competitive markets. However, given the specific characteristics of each country, the question we want to address is if fuel prices across EU members behave differently in response to different market structures. Oil operators have been targeted by competition authorities for conducting non-competitive practices. To figure out whether the common complaint that gasoline prices adjust differently to positive or negative input price changes, dynamic asymmetric models for the mean and variance are developed for each country. Several asymmetric specifications for the mean and variance are considered and the best specification combines double threshold error correction models (DT-ECM) for the mean with asymmetric EGARCH plus dummy variables for the conditional variance. We show that French gasoline prices behave more competitively, adjusting quicker to the long-run equilibrium and with higher price volatility. This outcome is consistent with the strong presence of hypermarkets following low-cost pricing strategies in France.