This paper presents an adaptive version of the Hill estimator based on Lespki’s model selection method. This simple data-driven index selection method is shown to satisfy an oracle inequality and is checked to achieve the lower bound recently derived by Carpentier and Kim. In order to establish the oracle inequality, we derive non-asymptotic variance bounds and concentration inequalities for Hi...

The concentration index is widely used to measure income-related inequality in health. No insight exists, however, whether the concentration index connects with people's preferences about distributions of income and health and whether a reduction in the concentration index reflects an increase in social welfare. We explored this question by testing the central assumption underlying the concentr...

Crop diversification is a strategy used by producers to address their household food insecurity. This study analyzes the factors that influence households’ decision participate in crop on plot and determinants of level based survey data obtained through stratified sampling Tonkpi, Poro Tchologo regions 2020. The Herfindahl index was classify according degree diversification. Applying Cragg hurd...

We study theoretically and empirically the relationship between investor beliefs, ownership dispersion stock returns. find that high dispersion, measured by breadth or low Herfindahl index, forecasts returns positively for large stocks, as in Chen, Hong Stein (2002), but negatively small stocks. explain a difference-of-opinion model which stocks differ size of disagreements extent belief polari...

Livestock markets are characterised by imperfections, distortions, and efficiency problems that impact livestock marketing. The purpose of this research was to analyse the sheep goat marketing system in Benin using structure-conduct-performance (SCP) approach. Primary data were collected from 215 small ruminant traders selected 21 calculate market concentration degree, margin, efficiency. four ...

Merger, acquisition and alliance events have been taking place since 2001 in the higher education sector private Brazilian. This resulted expansion of educational groups from foreign investment. The study evaluates data 55 institutions six between years 2014 2017. It was possible to verify that a restructuring is underway by calculating Hirschman-Herfindahl index. In light application DEA metho...

In knowledge-based economy, knowledge has a public good and non-rivalry nature. Firms build their own knowledge stock not only by means of internal R&D and collaboration with partners, but also by means of previously spilled over knowledge of other firms and public research laboratories (such as universities). Firms based on their absorptive capacity, and level of intra-industry and extra-indus...