[PEN-L:7003] Re: Alternatives to Herfindahl Index

[dilek cetindamar karaomerlioglu]

>Does anyone know of any alternative/unconventional (but reasonable) 
>measures of market concentration other than the Herfindahl Index?

some suggestions:
consider i= industry  s= PMSA     SUMs = summation over PMSA s  
CONi=concentration of industry i     EMPis Employment of industry i at PMSA s;
then concentration can be calculated by one of the followings:

a) CONi=100 - ½* [SUMs abs[(SUMs EMPis / SUMi SUMs EMPis )-(EMPis / SUMi
EMPis )]  
b) CONi= SUMi [(SUMs EMPis / SUMi SUMs EMPis )  - SUMs EMPis/n] square / 
              [1-SUMi  SUMs (EMPis/n) square ]

c) Gini coefficient = 0.5 * [1 - (SUMs EMPis / SUMi SUMs EMPis ) * (Qs + Qs-1 )]

Qs is the cumulative share of the first s PMSA’s total employment.


hope, it is helpful.

salud,
dilek cetindamar karaomerlioglu