Choice of the ridge factor from the correlation matrix determinant

Ridge regression is the alternative method to ordinary least squares, which is mostly applied when a multiple linear regression model presents a worrying degree of collinearity. A relevant topic in ridge regression is the selection of the ridge parameter, and different proposals have been presented in the scientific literature. Since the ridge estimator is biased, its estimation is normally based on the calculation of the mean square error (MSE) without considering (to the best of our knowledge) whether the proposed value for the ridge parameter really mitigates the collinearity. With this goal and different simulations, this paper proposes to estimate the ridge parameter from the determinant of the matrix of correlation of the data, which verifies that the variance inflation factor (VIF) is lower than the traditionally established threshold. The possible relation between the VIF and the determinant of the matrix of correlation is also analysed. Finally, the contribution is illustrated with three real examples

Procesos y herramientas documentales para el Periodismo de datos

El objetivo del presente trabajo es analizar los procesos y herramientas documentales que se emplean en el Periodismo de datos en España. Se parte de la definición, características, bases de trabajo y experiencias enmarcadas en esta clase de periodismo. A continuación, se explican los vínculos existentes entre la perspectiva documental y periodística. Finalmente, se describen diferentes experiencias para delimitar los puntos de encuentro especialmente referidos a fuentes de información y bases de datos. También se ha profundizado en los profesionales implicados en la elaboración del trabajo periodístico, así como en los datos colaterales, y los vinculados a la visualización de la información y los medios sociales

Herramientas interactivas y participación ciudadana en los ayuntamientos españoles

Los ayuntamientos, como instituciones más cercanas al conjunto social, mantienen el compromiso de ofrecer canales de participación e implicación del ciudadano en eldesarrollo de los municipios. Internet aporta una vía para conseguir este objetivo con una asombrosa eficacia, desconocida hasta su irrupción en la cotidianeidad. Las herramientas disponibles en la Red pueden resultar muy útiles para el mantenimiento constante y fluido de una relación comunicacional entre administradores públicos y ciudadanía. Este trabajo ofrece un análisis cuantitativo cuyo fin es comprobar si las citadas herramientas son parte integrante y básica en las páginas webs oficiales de los ayuntamientos de España.City councils, as institutions closer to the people, maintain the commitment to offer channels for the citizens to participate and get involved in the municipalities’ development. Internet provides a way to achieve this goal with remarkable efficiency, unknown until its burst into the everyday life. Network tools can be very useful to maintain a constant and fluid communication between government administrators and citizens. This report shows a quantitative analysis in order to check whether these tools are part of the basic oficial websites of the city councils in Spain

Detection of Near-Nulticollinearity through Centered and Noncentered Regression

This paper analyzes the diagnostic of near-multicollinearity in a multiple linear regression from auxiliary centered (with intercept) and noncentered (without intercept) regressions. From these auxiliary regressions, the centered and noncentered variance inflation factors (VIFs) are calculated. An expression is also presented that relates both of them. In addition, this paper analyzes why the VIF is not able to detect the relation between the intercept and the rest of the independent variables of an econometric model. At the same time, an analysis is also provided to determine how the auxiliary regression applied to calculate the VIF can be useful to detect this kind of multicollinearity.University of Almeri

Variance Inflation Factor and Condition Number in multiple linear regression

The Variance Inflation Factor and the Condition Number are measures traditionally applied to detect the presence of collinearity in a multiple linear model. This paper presents the relation and the difference between both measures from theoretical and empirical perspectives by using Monte Carlo simulations and taking special interest in the computational techniques

Limitations in detecting multicollinearity due to scaling issues in the “mcvis” package

Transformation of the observed data is a very common practice when a troubling degree of near multicollinearity is detected in a linear regression model. However, it is important to take into account that these transformations may affect the detection of this problem, so they should not be performed systematically. In this paper we analyze the transformation of the data when applying the R package mcvis, showing that it only detects essential near multicollinearity when the studentise transformation is performed.This work has been supported by project PP2019-EI-02 of the University of Granada (Spain), by project A-SEJ-496-UGR20 of the Andalusian Government’s Counseling of Economic Transformation, Industry, Knowledge and Universities (Spain) and by project I+D+i PID2019-107767GA-I0 financed by MCIN/AEI/10.13039/501100011033

On kawara, autobiografía visual

Profesional en Estudios LiterariosPregrad