Eduardo Martínez-Budría

A multioutput cost function for the services of Spanish ports' infrastructure

A long run multioutput cost function for the infrastructure services of Spanish ports is estimated using 286 observations on 26 ports during 11 years. Cargo specific marginal costs and the degree of economies of scale and scope are calculated up to a port level. Results show that liquid bulk and non-containerised general cargo present the lowest and largest marginal cost, respectively. Increasing returns to scale are present in general and for each and every port. A scope analysis indicates that port specialisation is not appropriate from the viewpoint of infrastructure.

Adapting Productivity Theory to the Quadratic Cost Function. An Application to the Spanish Electric Sector

In this article we have adapted productivity analysis to the case of a cost model using a quadratic cost function and discrete data. The main theoretical result is a productivity index that can be decomposed into modified versions of the contribution of technical change and the effect of the variations in the scale of production. This framework has been applied to the study of the Spanish electric sector from 1985 to 1996, during which relevant regulatory changes were introduced in order to increase productivity. For this, a normalized quadratic cost function was estimated. The results show important productivity gains with both technical change and scale effect playing important roles.

Multiple Outputs in Port Cost Functions

By describing the technical process, in this article we argue that cargo that arrives in many different forms are distinct outputs of a port, whose services require inputs that can be grossly defined as labor, space, facilities, and equipment. Then we show theoretically and empirically that the use of aggregate output in the presence of distinct outputs causes erroneous conclusions on marginal costs, on economies of scale, and on optimal industry structure.

Structure, Functioning and Regulation of the Spanish Electricity Sector. The Legal Framework and the New Proposals for Reform

An electrical system consists of a series of distinct stages: generation, transmission, distribution and supply (merchandising) of electricity services to the end-users. The traditional organisational model assumes, implicitly or explicitly, the extension of a natural monopoly condition from some of these stages to others. This is a consequence of the presumptive existence of strong, vertically-integrated economies. On the other hand, an increasing number of studies have proposed the vertical disintegration of the sector, suggesting that the common ownership of the different stages of the electric sector should be replaced by the introduction of competition wherever possible. These ideas have been developed within the context of a critique of the traditional control structure, characteristic of natural monopolies, which has been emerging in the industrialised world since the 1980’ s. The emphasis has now shifted towards the internal efficiency of the companies involved, and to uncovering those faults in the regulatory system which do not allow the product to be obtained at minimum cost.

Exact Allocative and Technical Inefficiency Using the Normalized Quadratic Cost System

In this paper we have built a theoretical model using a normalized quadratic cost system to obtain expressions for actual input demand and cost as functions of three components: frontier, allocative and technical inefficiency. We have used the shadow prices approach in the line of exact decomposition that allows to solve Greenes problem. Using the normalized quadratic cost system has permited to isolate not only allocative inefficiency but also the technical one, as simple functions of both parameters and variables. The model allows to obtain individual and time varying technical and allocative inefficency measures when a panel data is available. This model has been applied to cargo handling in Spanish ports.

Analysis of the Evolution of Sovereign Bond Yields by Wavelet Techniques

The term ”wavelets” covers a set of resources from the mathematical analysis that have proven their efficiency in system identification on areas such as hydrology, geology, glaciology, climatology and energy resources optimization. The methodology undergone on systems engineering could be extrapolated to everything conceptualized as ”complex system” whatever its nature. The wavelet techniques provide the description of non-stationary components and the evolution of macroeconomic variables in the frequency domain. The identification of predominant frequential scales and transient effects in time series, highlights the multiresolucional analysis, that would be more difficult to treat with traditional methods of econometrics. A review of the literature will show the potential problems that can be solved with these techniques, such as prediction of benefits calculated on the evolution of the risk premium of a country, the extraction of symmetric macroeconomic shocks in country clusters, or detection of transient effects on the mutual influence of sovereign bonds between pairs of countries, among others. The dissertation will culminate in specific applications that show the power of wavelet techniques in identifying possible determinants and correlation of the evolution of sovereign bond yields in the euro area countries.