Price Premium for High-Efficiency Refrigerators and Calculation of Price-Elasticities for Close-Substitutes: Combining Hedonic Pricing and Demand Systems

21 p.

Evaluating the role of energy efficiency labels in the prices of household appliances: the case of refrigerators

4 p.

Economic Evaluation of Energy Efficiency Labelling in Domestic Appliances: the Spanish Market

30 p.

Markov Switching Risk Premium and the term structure of interest rates. Empirical evidence from US post-war interest rates

This paper considers the basic present value model of interest rates under rational expectations with two additional features. First, following McCallum (1994), the model assumes a policy reaction function where changes in the short-term interest rate are determined by the long-short spread. Second, the short-term interest rate and the risk premium processes are characterized by a Markov regime-switching model. Using US post-war interest rate data, this paper finds evidence that a two-regime switching model fits the data better than the basic model. The estimation results also show the presence of two alternative states displaying quite different features.

Skill premium effects on fertility and female labor force supply

Published as an article in: Journal of Population Economics, 2004, vol. 17, issue 1, pages 1-16.

Lowndes and Locke on the value of money

This paper was presented at the 11th Annual Conference of the European Society for the History of Economic Thought (ESHET).

The Impact of Firm Level Contracting on Wage Levels and Inequality: Spain 1995-2002

This paper provides microeconomic evidence on the variation over time of the firm-specific wage premium in Spain from 1995 to 2002, and its impact on wage inequality. We make use of two waves of a detailed linked employer-employee data set. In addition, a new data set with financial information on firms is used for 2002 to control as flexibly as possible for differences in the performance of firms (aggregated at industry level). To our knowledge, there is no microeconomic evidence on the dynamics of the firm-specific wage premium for Spain or for any other country with a similar institutional setting. Our results suggest that there is a clear tendency towards centralization in the collective bargaining process in Spain over this seven-year period, that the firm-level contract wage premium undergoes a substantial decrease, particularly for women, and finally that the "centralization" observed in the collective bargaining process has resulted in a slight decrease in wage inequality.

The effect of firm-level contracts on the structure of wages: evidence from matched employer-employee data

Revised: 2006-11

Accuracy in Copy Number Calling by qPCR and PRT : A Matter of DNA

7 p.

Fishing effort validation and substitution possibilities among components: the case study of the VIII division European anchovy fishery

Command and control regulation programs, particularly input constraints, typically fail to achieve stated objectives, because fishermen may substitute unregulated for regulated inputs. It is, thus, essential to have an understanding of the internal structure of production technology. A primal formulation is used to estimate a translog production function at the vessels level that includes fishing effort and fisherman’s skill. The flexibility of the selected functional permits the analysis of the substitution possibilities among inputs by estimating the elasticity of substitution with no prior constraints. Particular attention is paid to the empirical validation of fishing effort as an aggregate input, which implies either, the acceptation of the joint hypothesis that inputs making up effort are weakly separable from the inputs out of the subgroup or considering that effort is an intermediate input produced by a non-separable two stage technology. Cross sectional data from the Spanish purse seine fleet operating in the VIII Division European anchovy fishery provide evidence of limited input substitution possibilities among the inputs making up the empirically validated fishing effort translog micro-production function.

Increased physical activity is not enough to recover astrocytic population from dark-rearing. Synergy with multisensory enrichment is required

10 p.

Local and Global Externalities, Environmental Policies and Growth

33 p.

Understanding Public Support for Externality-Correcting Taxes and Subsidies: A Lab Experiment

31 p.

Physiological modules for generating discrete and rhythmic movements: action identification by a dynamic recurrent neural network

In this study we employed a dynamic recurrent neural network (DRNN) in a novel fashion to reveal characteristics of control modules underlying the generation of muscle activations when drawing figures with the outstretched arm. We asked healthy human subjects to perform four different figure-eight movements in each of two workspaces (frontal plane and sagittal plane). We then trained a DRNN to predict the movement of the wrist from information in the EMG signals from seven different muscles. We trained different instances of the same network on a single movement direction, on all four movement directions in a single movement plane, or on all eight possible movement patterns and looked at the ability of the DRNN to generalize and predict movements for trials that were not included in the training set. Within a single movement plane, a DRNN trained on one movement direction was not able to predict movements of the hand for trials in the other three directions, but a DRNN trained simultaneously on all four movement directions could generalize across movement directions within the same plane. Similarly, the DRNN was able to reproduce the kinematics of the hand for both movement planes, but only if it was trained on examples performed in each one. As we will discuss, these results indicate that there are important dynamical constraints on the mapping of EMG to hand movement that depend on both the time sequence of the movement and on the anatomical constraints of the musculoskeletal system. In a second step, we injected EMG signals constructed from different synergies derived by the PCA in order to identify the mechanical significance of each of these components. From these results, one can surmise that discrete-rhythmic movements may be constructed from three different fundamental modules, one regulating the co-activation of all muscles over the time span of the movement and two others elliciting patterns of reciprocal activation operating in orthogonal directions.

Physiological modules for generating discrete and rhythmic movements: Component analysis of EMG signals

A central question in Neuroscience is that of how the nervous system generates the spatiotemporal commands needed to realize complex gestures, such as handwriting. A key postulate is that the central nervous system (CNS) builds up complex movements from a set of simpler motor primitives or control modules. In this study we examined the control modules underlying the generation of muscle activations when performing different types of movement: discrete, point-to-point movements in eight different directions and continuous figure-eight movements in both the normal, upright orientation and rotated 90 degrees. To test for the effects of biomechanical constraints, movements were performed in the frontal-parallel or sagittal planes, corresponding to two different nominal flexion/abduction postures of the shoulder. In all cases we measured limb kinematics and surface electromyographic activity (EMB) signals for seven different muscles acting around the shoulder. We first performed principal component analysis (PCA) of the EMG signals on a movement-by-movement basis. We found a surprisingly consistent pattern of muscle groupings across movement types and movement planes, although we could detect systematic differences between the PCs derived from movements performed in each sholder posture and between the principal components associated with the different orientations of the figure. Unexpectedly we found no systematic differences between the figute eights and the point-to-point movements. The first three principal components could be associated with a general co-contraction of all seven muscles plus two patterns of reciprocal activatoin. From these results, we surmise that both "discrete-rhythmic movements" such as the figure eight, and discrete point-to-point movement may be constructed from three different fundamental modules, one regulating the impedance of the limb over the time span of the movement and two others operating to generate movement, one aligned with the vertical and the other aligned with the horizontal.