Measuring Inequality in CIS Countries: Theory and Empirics

Distributions of many variables of interest in developed economic and financial markets, including income and wealth, exhibit heavy tails as in the case of Pareto or power laws. Many commonly used income and wealth inequality measures are very sensitive to extremes and outliers generated by these distributions due to their heavy-tailedness properties. This paper focuses on robust analysis of distributions and heavy-tailedness characteristics for data on income and wealth for the World, Russia and post-Soviet Central Asian economies. Among other results, it provides robust estimates of heavy-tailedness parameters for income and wealth in the markets considered and their comparisons with the benchmark values that are well-established for distributions of these variables in developed economies. The paper further provides applications of the obtained empirical results to inference on inequality measures and discusses their implications for market demand and economic equilibrium.Income inequality, wealth inequality, CIS countries, Russian economy, post-Soviet economies, heavy-tailedness, power laws, Pareto distribution, income inequality, market demand, economic equilibrium

Optimal Constants in the Rosenthal Inequality for Random Variables with Zero Odd Moments.

We obtain estimates for the best constant in the Rosenthal inequality View the MathML source for independent random variables ξ1,…,ξn with l zero first odd moments, lgreater-or-equal, slanted1. The estimates are sharp in the extremal cases l=1 and l=m, that is, in the cases of random variables with zero mean and random variables with m zero first odd moments.Economic

Market Demand Elasticity and Income Inequality

This paper deals with the analysis of the relation between aggregate demand for a consumption good and the distribution of income across consumers. We obtain sufficient conditions under which changes in income inequality lead to an increase or decrease in the market demand elasticities. The conditions are satisfied for individual demand functions commonly used in economic models, in particular, for the typical demand functions on luxury goods and necessities.Economic

Optimization of construction time regulations for large-panel residential buildings

The need to modernize residential construction technologies is an imperative for reducing labour, material, technical, fuel and energy resources. The purpose of the study is to optimize the construction time regulations for the large-panel residential buildings by synchronizing construction flows. The methodological basis contains the principles of climatic zoning for building construction and technical regulation, affecting the particular features of architectural design and the construction schedule. A technique for the combination of maximum allowable types of work under continuous construction arrangement has been developed and coefficient of combination of different types of work for construction flows synchronization has been determined. The practical significance of the study is to improve the process of exterior wall panels installation, provided that an integrated regulation model based on the Spider Project software package is used. The social significance of the study is to make the reduction of the construction time and saving resources possible. The originality of the study is that the combining of different work types during the installation of exterior wall panels of a large-panel residential building has been justified. The need for creation of regional regulations for the construction time has been proved

Broad-band spectra of Cyg X-1 and correlations between spectral characteristics

We present the results of spectral analysis of 42 simultaneous broad-band Ginga--OSSE and RXTE--OSSE observations of Cyg X-1 carried out in 1991 and 1996--1999. The hardest spectra in our sample in the energy range from 3 to \~1000 keV can be well described by thermal Comptonization model with reflection from the cold disc, while the rest of the spectra are more complex and require an additional component below 10 keV. We consider a number of physically realistic models to describe the shape of the E<10 keV excess. The additional soft component can result from thermal Comptonization by electrons with a low Compton parameter, or can be a part of a nonthermal, power-law like emission extending above 1 MeV. We study correlations between parameters obtained from the spectral fits with different models. We confirm a general correlation between the photon index $\Gamma$ and the amplitude of reflection R. We find that simple phenomenological models (like power-law plus Compton reflection) applied to the narrow band (3--20 keV) data overestimated the values of R and $\Gamma$, although the simple models did rank correctly the spectra according to R and $\Gamma$. The dynamic corona model provides a satisfactory description of the observed correlation, while the hot inner disc models have problems in reproducing it quantitatively. We do not find significant correlation between the electron temperature and other spectral parameters, while the optical depth of the hot medium seems to decrease when the spectrum becomes softer. It is also shown that spectral parameters are well correlated with the timing characteristics of the source.Comment: 17 pages, 11 figures, accepted to MNRAS. Changes to v2: added N_H notes, improved discussion on timing, new calibration use

Customer Search and Product Returns

Online retailers are challenged by frequent product returns. High return rates significantly decrease companies’ profit which makes the issue of managing product returns very important from the practical standpoint. Typically, practitioners study returns in connection with purchase decisions or as a part of customer behavior/type. In this paper, we show that the events which precede the purchase decision are related to the return decision. Generally, this information is readily available to online retailers and thus provides a low-cost opportunity to better understand and predict the product returns. Based on the data provided by a large apparel retailer, we demonstrate that the way customers search for a product is indicative of product returns. We find correlational evidence that using search filters, spending more time, and purchasing the last item searched are negatively associated with the probability of return. We propose a joint model of search, purchase and return which is based on an analytic model of search, purchase, and returns. Our model is consistent with the findings in the data and provides insight into how search and returns are related. Finally, using a machine learning framework, we demonstrate that adding search data improves the prediction accuracy of individual-level return rate above and beyond prior models.S.M

Optimal constants in the Rosenthal inequality for random variables with zero odd moments

We obtain estimates for the best constant in the Rosenthal inequality for independent random variables [xi]1,...,[xi]n with l zero first odd moments, l[greater-or-equal, slanted]1. The estimates are sharp in the extremal cases l=1 and l=m, that is, in the cases of random variables with zero mean and random variables with m zero first odd moments.Rosenthal inequality Moment inequalities Best constants

A method of calculating the spectral radius of a nonnegative matrix and its applications

We present a method of calculating the maximal eigenvalue of an indecomposable nonnegative matrix, which is based on ideas of geometric programming. In addition to that, we obtain estimates for elements of an indecomposable nonnegative matrix by its spectral radius. The results make it possible to obtain new necessary conditions for the productivity of the matrix of coefficients in the Leontief input-output model and have the immediate relation to the analysis of M- matrices. Another interesting application of the developed method is given by conditions of stability of the dynamic system of market equilibrium.Leontief model, Productiviy, Market equilibrium, Spectral radius, M-matrices, Geometric programming.

Heavy-tailed distributions and robustness in economics and finance

This book focuses on general frameworks for modeling heavy-tailed distributions in economics, finance, econometrics, statistics, risk management and insurance. A central theme is that of (non-)robustness, i.e., the fact that the presence of heavy tails can either reinforce or reverse the implications of a number of models in these fields, depending on the degree of heavy-tailedness. These results motivate the development and applications of robust inference approaches under heavy tails, heterogeneity and dependence in observations. Several recently developed robust inference approaches are discussed and illustrated, together with applications