Is Ownership Structure a Determinant of Bank Efficiency?

When owners could easily sell a company if it is not performing well enough provide additional incentive to the administration to act in the best interest of the stockholders, since in the merger process the actual administration will lose their job (Jensen and Ruback, 1983; Schranz, 1993). It is difficult to test this hypothesis empirically due to the difficulty in measuring some of these concepts. This paper uses cost and profit functions to estimate efficiency at the bank level in Chile. Based on these measures, we explain cross-bank differences over time, which are related to bank size, ownership structure, and other relevant variables. We report two main findings. First, banks that are established as listed companies in Chile tend to show a higher level of efficiency than those established as closed companies. This result holds even after controlling for the bank’s product mix and property origin (domestic versus foreign). Our interpretation of this result is that listed banks have a relatively high probability of takeover in Chile, since the ownership structure is known. Managers therefore act in the best interest of stockholders. Second, banks that have a high property concentration demonstrate a high level of efficiency. The two results together suggest that mitigation of the principal-agent problem is key to explaining bank efficiency.

Nota técnica para estimar fronteras estocásticas: una aplicación a la banca chilena

This is a technical note on the estimation of Stochastic Frontiers, based on the specifications of Battese and Coelli (1992) and Cornwell and Schmidt (1990). We focus on the functional form that one should use to estimate technical efficiency, cost and profit of the Chilean banking system. Three functional forms are specified: Fourier Flexible, Translog and Cobb Douglas. The LR and Fisher tests show that the frontier of the Chilean banking sector should be estimated by a Fourier Flexible. The results also show that Translog and Cobb-Douglas could underestimate bank efficiency. Moreover, the tests reject the hypothesis of efficiency persistence, that is to say efficiency does not remain constant over time. Finally, Hausman's test do not reveal significant differences between the models of Stochastic Frontiers and Fixed Effect. This means that the distributional assumptions and that of absence of correlation between the exogenous variables and efficiency imposed by Stochastic Frontier are not rejected.Esta investigación elabora una nota técnica para estimar fronteras estocásticas. Para ello se utiliza la especificación de Battese and Coelli (1992) y Cornwell and Schmidt (1990). Se investiga la forma funcional que se debe utilizar para aproximar la eficiencia técnica, costo y beneficio del sistema bancario chileno. Para ello se especifican tres formas funcionales: Fourier flexible, Translog y Cobb Douglas. Los tests LR y Fisher muestran que la frontera de la banca chilena debe ser aproximada por una Fourier flexible. Además, la evidencia muestra aumento en el nivel de eficiencia costo y beneficio de utilizar esta forma funcional, lo cual indica que Translog y Cobb-Douglas podrían subestimar la eficiencia de la banca. También los tests rechazan la hipótesis de persistencia de la eficiencia, es decir, ésta no permanece constante en el tiempo. Finalmente, el test de Hausman no revela diferencias significativas entre el modelo frontera estocástica y efecto fijo. Esto significa que los supuestos distribucional y de no correlación entre las variables exógenas y la eficiencia impuestos por frontera estocástica no se rechazan

Space-Time Diffeomorphisms in Noncommutative Gauge Theories

In previous work [Rosenbaum M. et al., J. Phys. A: Math. Theor. 40 (2007), 10367-10382, hep-th/0611160] we have shown how for canonical parametrized field theories, where space-time is placed on the same footing as the other fields in the theory, the representation of space-time diffeomorphisms provides a very convenient scheme for analyzing the induced twisted deformation of these diffeomorphisms, as a result of the space-time noncommutativity. However, for gauge field theories (and of course also for canonical geometrodynamics) where the Poisson brackets of the constraints explicitely depend on the embedding variables, this Poisson algebra cannot be connected directly with a representation of the complete Lie algebra of space-time diffeomorphisms, because not all the field variables turn out to have a dynamical character [Isham C.J., Kuchar K.V., Ann. Physics 164 (1985), 288-315, 316-333]. Nonetheless, such an homomorphic mapping can be recuperated by first modifying the original action and then adding additional constraints in the formalism in order to retrieve the original theory, as shown by Kuchar and Stone for the case of the parametrized Maxwell field in [Kuchar K.V., Stone S.L., Classical Quantum Gravity 4 (1987), 319-328]. Making use of a combination of all of these ideas, we are therefore able to apply our canonical reparametrization approach in order to derive the deformed Lie algebra of the noncommutative space-time diffeomorphisms as well as to consider how gauge transformations act on the twisted algebras of gauge and particle fields. Thus, hopefully, adding clarification on some outstanding issues in the literature concerning the symmetries for gauge theories in noncommutative space-times.Comment: This is a contribution to the Special Issue on Deformation Quantization, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

R-based library for heuristic generation of decision trees

Se ha implementado una API en R para la generación de árboles de decisión. Se ha trabajado con un fichero de datos, con una serie de síntomas que han provocado una enfermedad, que ha sido depurado posteriormente. Hemos implementado una función en la que, a partir del fichero de datos y un conjunto de síntomas ordenados a nuestra elección, se crea el árbol de decisión que en cada elección escogerá el síntoma indicado anteriormente. El siguiente paso ha sido crear dos funciones de predicción que nos sirvan para comparar los resultados reales con los resultados obtenidos por el árbol de decisión. Tras construir el árbol y las funciones de predicción, crearemos una función que unificará ambas tareas. Este método será la validación cruzada que nos permitirá obtener mejores resultados. Finalmente, se ha realizado una comparación de los resultados obtenidos con nuestro método y los resultados extraídos por los algoritmos existentes hasta la actualidad. La implementación de todas las funciones se ha llevado a cabo con el programa estadístico R, mientras que para la comparación de resultados se ha utilizado la herramienta de minería de datos Weka

Residuos en dominios Euclidianos

En este trabajo, se caracteriza a los dominios euclidianos de resto único analizando las unidades para así determinar si es un campo o un anillo de polinomios sobre un campo. Se determinan a los dominios euclidianos con resto doble, mediante algunas estructuras cociente y un argumento de inducción para concluir que son isomorfos a los anillos de los numeros enteros. Presentamos además ejemplos de dominios euclidianos con resto múltiple mayor a dos

Determinantes de la productividad de los bancos en Chile

This research analyzes the decomposition of the total factorproductivity (TFP) for the Chilean banking sector. We use twomethodologies to accomplish this goal: Stochastic FrontierApproach and Data Envelopment Analysis. The decompositionsconsider technical efficiency, scope efficiency, and technologicalprogress. The last factor is the most important driven for TPF. Wewere able to reject the usual hypothesis that public financialinstitutions are less efficient than the private banking. In addition,potential banks candidates of a takeover tend to be more productiveand the evidence not supports the hypothesis that foreign banks aremore efficient than domestic.Esta investigación estudia la descomposición de la productividad total de los factores (PTF) del sistema bancario chileno. Se utilizandos metodologías: fronteras estocásticas y análisis de la envolvente de datos. Se descomponen la PTF en eficiencia técnica, escala y cambio tecnológico. En ambos métodos el determinante de mayor peso es el cambio tecnológico. No podemos rechazar la hipótesis que la banca privada tenga un mejor desempeño que la pública.Además los bancos, potenciales candidatos de una toma de control,tienden a ser más productivos. Finalmente, la evidencia no respalda la hipótesis que los bancos extranjeros son más eficientes que los domésticos