Estimating the empirical Lorenz curve and Gini coefficient in the presence of error with nested data Journal Article


Authors: Moskowitz, C. S.; Seshan, V. E.; Riedel, E. R.; Begg, C. B.
Article Title: Estimating the empirical Lorenz curve and Gini coefficient in the presence of error with nested data
Abstract: The Lorenz curve is a graphical tool that is widely used to characterize the concentration of a measure in a population, such as wealth. It is frequently the case that the measure of interest used to rank experimental units when estimating the empirical Lorenz curve, and the corresponding Gini coefficient, is subject to random error. This error can result in an incorrect ranking of experimental units which inevitably leads to a curve that exaggerates the degree of concentration (variation) in the population. We consider a specific data configuration with a hierarchical structure where multiple observations are aggregated within experimental units to form the outcome whose distribution is of interest. Within this context, we explore this bias and discuss several widely available statistical methods that have the potential to reduce or remove the bias in the empirical Lorenz curve. The properties of these methods are examined and compared in a simulation study. This work is motivated by a health outcomes application that seeks to assess the concentration of black patient visits among primary care physicians. The methods are illustrated on data from this study. Copyright © 2008 John Wiley & Sons, Ltd.
Keywords: united states; bayes theorem; analytic method; medicare; population research; statistical analysis; models, statistical; data analysis; logistic regression analysis; mathematical computing; quality of health care; analytical error; primary health care; african continental ancestry group; distribution; bootstrapping; concentration; hierarchical data; inequality; gini coefficient; lorenz curve; population distribution; random error
Journal Title: Statistics in Medicine
Volume: 27
Issue: 16
ISSN: 0277-6715
Publisher: John Wiley & Sons  
Date Published: 2008-07-20
Start Page: 3191
End Page: 3208
Language: English
DOI: 10.1002/sim.3151
PUBMED: 18172873
PROVIDER: scopus
PMCID: PMC3465674
DOI/URL:
Notes: --- - "Cited By (since 1996): 2" - "Export Date: 17 November 2011" - "CODEN: SMEDD" - "Source: Scopus"
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  1. Colin B Begg
    306 Begg
  2. Chaya S. Moskowitz
    278 Moskowitz