Polychoric versus Pearson correlations in exploratory and confirmatory factor analysis of ordinal variables

Given that the use of Likert scales is increasingly common in the field of social research it is necessary to determine which methodology is the most suitable for analysing the data obtained; although, given the categorization of these scales, the results should be treated as ordinal data it is often the case that they are analysed using techniques designed for cardinal measures. One of the most widely used techniques for studying the construct validity of data is factor analysis, whether exploratory or confirmatory, and this method uses correlation matrices (generally Pearson) to obtain factor solutions. In this context, and by means of simulation studies, we aim to illustrate the advantages of using polychoric rather than Pearson correlations, taking into account that the latter require quantitative variables measured in intervals, and that the relationship between these variables has to be monotonic. The results show that the solutions obtained using polychoric correlations provide a more accurate reproduction of the measurement model used to generate the data.     

Demand Shocks and Trade Balance Dynamics

This paper studies the trade balance dynamics in the G-7 countries plus Spain. We estimate a SVAR model to identify three different shocks: real supply shocks, real demand disturbances and nominal shocks. A microfounded stochastic open-economy model is built to derive the long-term identification restrictions. Estimates show that real demand shocks explain most of the variability of trade imbalances, whereas, contrary to previous findings, nominal shocks play a very limited role. These results are consistent with the predictions of a widely set of open-economy models and illustrate that demand policies are the main responsible of trade imbalances.     

Technical efficiency and productivity changes in Spanish airports: A parametric distance functions approach

This paper contributes to the airport benchmarking literature in two ways. To our knowledge, this is the first attempt at using a stochastic distance function to measure airports’ productivity changes while considering multiple outputs. Secondly, we calculate the evolution and decomposition of the Total Factor Productivity (TFP) for Spanish airports. The average rate of productivity showed a slight annual improvement of 0.9%, and the core engine of this was 3% increase in technical progress rather than through efficiency. Results, by airport, identify those needing improvement, to be more attractive in the Spanish airport restructuring program.     

Alternative Models for Describing Spatial Dependence among Dwelling Selling Prices

In this article different spatial statistics techniques to analyze the behavior of used dwelling market prices are compared. We fit two lattice models: simultaneous and conditional autoregressive, a geostatistical model, the so-called universal kriging and finally, a linear mixed-effect model. Different spatial neighborhood structures are considered, as well as different spatial weight matrices and covariance models. The results are illustrated through a real data set of 293 properties from Pamplona, Spain.     

Efficiency and Equity in Natural Resources Pricing: A Proposal for Urban Water Distribution Service

This paper focuses on the design of optimal prices for urban water distribution service. In this context, pricing should be aimed at achieving efficiency, equity, financial aspects, and/or public acceptability and transparency. The proposed tariffs are based on the theoretical frameworks suggested by Ramsey (1927) and Feldstein (1972). As a prior step, estimations of urban water demands and water costs are carried out for the Spanish municipality of Seville. Finally, an empirical comparison, in welfare terms, is conducted between the proposed tariffs and those applicable in the year 2000.     

Are More Innovative Firms Less Vulnerable to New Environmental Regulation?

Compliance with pollution limits and standards requires firms to implement adaptation processes that are not only costly themselves but also affect future profits in as much as they modify production systems and methods. This paper attempts to respond to the question of how technological knowledge moderates the effect that the implementation of a new environmental regulation has on the results of affected firms. The regulation selected for this study is the Integrated Pollution Prevention and Control Act (IPPC). A Multivariate Regression Model (MVRM) has been applied to the regulatory event. The most important implication of this paper is that technological knowledge prepares a firm for adapting to a greater environmental demand such as may be derived from a new regulation. This paper has been developed under the objectives of the CREVALOR Research Group (DGA-Spain). Moreover, it has been financed by the MEC-FEDER Research Project SEJ2005-07341.     

Firm-provided training and temporary contracts

This paper analyses the relationship between workers type of contract and the probability of receiving firm-provided training. In particular, we raise the following question: do workers with temporary contracts face the same probability of receiving training as workers with permanent contracts, once we account for the fact that both types of workers have different probabilities of being employed in a firm providing training? The results from our empirical analysis using data from the Spanish labour market suggest that workers with temporary contracts not only are less likely to be employed in training firms but, once they are in those firms, they also have a lower probability of being chosen to participate in firm-provided training activities.JEL Classification: J23, M53Authors gratefully acknowledge financial support from Universidad de Alcalá under research project La relación entre temporalidad y formación en la empresa: un análisis comparativo entre los países de la Unión Europea (award no. UAH2002/022) and from the Spanish Ministry of Science and Technology under research project Observatorio del mercado de trabajo (SEC2001-0061). We have also benefited from our participation in the research project Estudio sobre la situación actual de la contratación temporal e indefinida en España financed by the Spanish Employment Office (INEM). We are grateful to participants in the XXVII Simposio de Análisis Económico (Salamanca), V Jornadas de Economía Laboral (Reus-Tarragona), and a seminar in the Istituto de Ricerca Sociale (Milano), and to one anonymous referee. The usual disclaimer applies.     

Are outsourcing and non-aeronautical revenues important drivers in the efficiency of Spanish airports?

This paper evaluates the influence of contracting out, or outsourcing, certain airport services and of commercial diversification strategy. Although most of the effort is being put towards applying non-parametric techniques in airport efficiency studies, we have chosen parametric methodology. We use a distance function, as it has known advantages. The findings show the positive contribution of outsourcing and non-aeronautical revenues on the efficiency of the Spanish airports' network.