Herfindahl-Hirschman Index (HHI) with Panel Data

[Bobby Killins]

Hello,

I have a data set with 38 firms with quarterly data spanning from 1996 to 2018. I would like to create an HHI index based on total revenue for dataset.

Variable name:

Revenue: totalrevenue
Time: quarter1
Firm identifier: firmid

Thanks for any help.

[Nick Cox]

See FAQ Advice #12 for explanation of why screenshots are much less helpful than you want.

A search of the archives formentions of entropyetc (SSC) will find some of many, many relevant threads. A search for Hirschman or Herfindahl will find even more.

[River Huang]

In addition Nick's excellent advice, you might want to search -hhi5- and install.