Tsallis statistics and gradually truncated Levy flight - distribution of an economical index

Tsallis postulated a generalized form for entropy and give rise to a new statistics now known as Tsallis statistics. In the present work, we compare the Tsallis statistics with the gradually truncated Levy flight, and discuss the distribution of an economical index-the Standard and Poor's 500-using the values of standard deviation as calculated by our model. We find that both statistics give almost the same distribution. Thus we feel that gradual truncation of Levy distribution, after certain critical step size for describing complex systems, is a requirement of generalized thermodynamics or similar. The gradually truncated Levy flight is based on physical considerations and bring a better physical picture of the dynamics of the whole system. Tsallis statistics gives a theoretical support. Both statistics together can be utilized for the development of a more exact portfolio theory or to understand better the complexities in human and financial behaviors. A comparison of both statistics is made. (C) 2002 Published by Elsevier B.V. B.V.

Gini coefficient, dissimilarity index and Lorenz curve for the spanish port system by type of goods

This paper shows the Gini Coefficient, the dissimilarity Index and the Lorenz Curve for the Spanish Port System by type of goods from 1960 to the year 2010 for business units: Total traffic, Liquid bulk cargo, Solid bulk cargo, General Merchandise and Container (TEUs) with the aim of carcaterizar the Spanish port systems in these periods and propose future strategies.

Efficiency and productivity of Singapore’s manufacturing sector 2001-2010: An analysis using Simar and Wilson’s (2007) bootstrapped truncated approach

This paper seeks to explain the lagging productivity in Singapore’s manufacturing noted in the statements of the Economic Strategies Committee Report 2010. Two methods are employed: the Malmquist productivity to measure total factor productivity change and Simar and Wilson’s (J Econ, 136:31–64, 2007) bootstrapped truncated regression approach. In the first stage, the nonparametric data envelopment analysis is used to measure technical efficiency. To quantify the economic drivers underlying inefficiencies, the second stage employs a bootstrapped truncated regression whereby bias-corrected efficiency estimates are regressed against explanatory variables. The findings reveal that growth in total factor productivity was attributed to efficiency change with no technical progress. Most industries were technically inefficient throughout the period except for ‘Pharmaceutical Products’. Sources of efficiency were attributed to quality of worker and flexible work arrangements while incessant use of foreign workers lowered efficiency.

Using the Gini coefficient with BIOLOG substrate utilisation data to provide an alternative quantitative measure for comparing bacterial soil communities

A measure quantifying unequal use of carbon sources, the Gini coefficient (G), has been developed to allow comparisons of the observed functional diversity of bacterial soil communities. This approach was applied to the analysis of substrate utilisation data obtained from using BIOLOG microtiter plates in a study which compared decomposition processes in two contrasting plant substrates in two different soils. The relevance of applying the Gini coefficient as a measure of observed functional diversity, for soil bacterial communities is evaluated against the Shannon index (H) and average well colour development (AWCD), a measure of the total microbial activity. Correlation analysis and analysis of variance of the experimental data show that the Gini coefficient, the Shannon index and AWCD provided similar information when used in isolation. However, analyses based on the Gini coefficient and the Shannon index, when total activity on the microtiter plates was maintained constant (i.e. AWCD as a covariate), indicate that additional information about the distribution of carbon sources being utilised can be obtained. We demonstrate that the Lorenz curve and its measure of inequality, the Gini coefficient, provides not only comparable information to AWCD and the Shannon index but when used together with AWCD encompasses measures of total microbial activity and absorbance inequality across all the carbon sources. This information is especially relevant for comparing the observed functional diversity of soil microbial communities.

Power-law distributions for the citation index of scientific publications and scientists

The number of citations of a scientific publication or of an individual scientist has become an important factor of quality assessment in science. We report a study of the statistical distribution of the citation index of both scientific publications and scientists. We give numerical evidence that Tsallis (power law) statistics explains the entire distribution over eight orders of magnitude (10-4 to 10(4)). Also, we draw Zipf plots in order to analyze the statistical distribution of the citation index of Brazilian and international physicists and chemists. The relatively small group of Brazilian scientists seems more adequate to explain the dynamics of the citation index. In this case, we find that the distribution of the citation index can also be explained by a gradually truncated power law with similar parameters. We finally discuss possible mechanisms behind the citation index of scientists and scientific publications.

The gradually truncated Levy flight for systems with power-law distributions

Power-law distributions have been observed in various economical and physical systems. Levy flights have infinite variance which discourage a physical approach. We introduce a class of stochastic processes, the gradually truncated Levy flight in which large steps of a Levy flight are gradually eliminated. It has finite variance and the system can be analyzed in a closed form. We applied the present method to explain the distribution of a particular economical index. The present method can be applied to describe time series in a variety of fields, i.e. turbulent flow, anomalous diffusion, polymers, etc. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Aportes para examinar las desigualdades educativas en los grandes centros urbanos : El uso del coeficiente de Gini para analizar la distribución del abandono escolar entre las escuelas secundarias de la Ciudad Autónoma de Buenos Aires

La Ley de Educación Nacional promulgada en 2006 en Argentina establece la obligatoriedad de la educación secundaria en todo el país, la Ciudad Autónoma de Buenos Aires ha sido pionera al respecto estableciendo esta meta en el año 2002. En este marco, se propone analizar los desafíos que este tipo de política enfrenta en la actualidad, centrando la atención en la capacidad de los sistemas e instituciones educativas para garantizar este derecho en términos de acceso, permanencia y promoción de los alumnos en el nivel secundario. Este trabajo tiene por objeto plantear un ejercicio de análisis del abandono escolar que ocurre durante el ciclo lectivo en las escuelas a partir de la consideración del análisis del porcentaje de alumnos "salidos sin pase", e incorporar, a la vez, una medida de dispersión (coeficiente de Gini) que permita visibilizar las desigualdades entre escuelas a nivel territorial en la Ciudad Autónoma de Buenos Aires

Aportes para examinar las desigualdades educativas en los grandes centros urbanos : El uso del coeficiente de Gini para analizar la distribución del abandono escolar entre las escuelas secundarias de la Ciudad Autónoma de Buenos Aires

La Ley de Educación Nacional promulgada en 2006 en Argentina establece la obligatoriedad de la educación secundaria en todo el país, la Ciudad Autónoma de Buenos Aires ha sido pionera al respecto estableciendo esta meta en el año 2002. En este marco, se propone analizar los desafíos que este tipo de política enfrenta en la actualidad, centrando la atención en la capacidad de los sistemas e instituciones educativas para garantizar este derecho en términos de acceso, permanencia y promoción de los alumnos en el nivel secundario. Este trabajo tiene por objeto plantear un ejercicio de análisis del abandono escolar que ocurre durante el ciclo lectivo en las escuelas a partir de la consideración del análisis del porcentaje de alumnos "salidos sin pase", e incorporar, a la vez, una medida de dispersión (coeficiente de Gini) que permita visibilizar las desigualdades entre escuelas a nivel territorial en la Ciudad Autónoma de Buenos Aires

Aportes para examinar las desigualdades educativas en los grandes centros urbanos : El uso del coeficiente de Gini para analizar la distribución del abandono escolar entre las escuelas secundarias de la Ciudad Autónoma de Buenos Aires

La Ley de Educación Nacional promulgada en 2006 en Argentina establece la obligatoriedad de la educación secundaria en todo el país, la Ciudad Autónoma de Buenos Aires ha sido pionera al respecto estableciendo esta meta en el año 2002. En este marco, se propone analizar los desafíos que este tipo de política enfrenta en la actualidad, centrando la atención en la capacidad de los sistemas e instituciones educativas para garantizar este derecho en términos de acceso, permanencia y promoción de los alumnos en el nivel secundario. Este trabajo tiene por objeto plantear un ejercicio de análisis del abandono escolar que ocurre durante el ciclo lectivo en las escuelas a partir de la consideración del análisis del porcentaje de alumnos "salidos sin pase", e incorporar, a la vez, una medida de dispersión (coeficiente de Gini) que permita visibilizar las desigualdades entre escuelas a nivel territorial en la Ciudad Autónoma de Buenos Aires

An R script to plot the conditioned Gini (or skewness) coefficient in the bivariate case

In the cs.index.zip file we provide an R script which let us plot the conditioned Gini (or skewness) coefficient used in the working paper entitled "On conditional skewness with applications in environmental data" submitted to Environmental and Ecological Statistics. On the other hand, the ReadMe.pdf explains how to use the cs.index.R script.