This paper utilizes maximum likelihood methods to simulate a Hirschman-Herfindahl index (HHI) for markets in which complete market share information is unavailable or delayed. Many jurisdictions eithe...
A Herfindahl index of constructed from shares based on count data where the number of counts is small will generally be biased downward because of the statistical properties of count data and Jensen?s...
OBJECTIVE: To examine the effect of surgeon specialization on patient outcomes, controlling for volume. BACKGROUND: There is great interest in the degree to which surgical specialization affects outco...