In recent years there have been marked changes in organisational structures and budgetary arrangements in the English NHS, potentially altering the relationships between purchasers (primary care organisations (PCOs) and general practices) and providers. Using data on elective hospital admissions from 1997/98 to 2002/03 we find that commissioning has become significantly more concentrated at PCO...

Total institutional ownership, institutional ownership by type of institution (e.g. banks, insurance companies, mutual funds), and a new measure of ownership concentration (similar to the Herfindahl Index) are used to explain contemporaneous bid-ask spreads for 72 quarters (1983-2000) of NASDAQtraded stocks. When controlling for a number of commonly-used variables, relative bid-ask spreads are ...

This article challenges recent research (Evans, 2008) reporting that the concentration of cited scientific literature increases with the online availability of articles and journals. Using Thomson Reuters’ Web of Science, the present article analyses changes in the concentration of citations received (2and 5-year citation windows) by papers published between 1900 and 2005.Three measures of conc...

The study aims to analyze the export performance of countries and of cities within them to identify synchronized or unsynchronized movement between them. In the empirical part of the study, the measurements used to analyze the export performance of the countries included in the literature are applied to establish the export performance of a single city-Sakarya, Turkey. These measurements includ...

INTRODUCTION Hospitals are studying the focused factory concept and attempting to increase their power in a competitive industry by becoming more specialized. METHODOLOGY This study uses the information theory index (ITI) and the Herfindahl-Hirschman index (HHI) to analyze the extent of specialization by Korean hospitals that receive national health insurance reimbursements. Hierarchical regr...

Risk analysis depends to a large extent on the type of data. Aggregate data can serve as a useful surrogate for individual data. However, in practice, there is uncertainty on the reliability and adequacy of aggregated data. In this paper we estimate the Herfindahl-Hirschman Index (HHI) for a loan portfolio using both aggregate data and individual data. Then, we compare both estimates to assess ...

The paper analyses the impact of geographic innovation on Total Factor Productivity (TFP) in Taiwan in 2001 using 242 four-digit standard industrial classification (SIC) industries. We compute TFP by estimating Translog production functions with K, L, E and M inputs, and measure the geographic innovative activity using both Krugman's Gini coefficients and the location Herfindahl index. We also ...

Experience shows that private or locally financed toll roads do not always reward their investors. This paper studies a case where investors in toll roads earned competitive returns on average but with wide variation in outcomes. The context is England and Wales during their early industrialization when private investors provided much of the capital to improve what were called turnpike trust ro...

the organization of the petroleum exporting countries (opec) has a key role in making universal political and economic decisions regarding petroleum. therefore, it seems highly important to assess the opec member’s degree of concentration and its monopoly.  this research, aims to assess and classify the concentration of petroleum export in the opec countries during the 1997-2011 period by the h...