Herfindahl - Hirschmann Index calculation issue

[Anuradha Saikia]

Hello everyone. I have followed almost all threads on HHI but still do not know what to do with negative sales values. the output says " Negative values in varlist".
. i am sorry but can someone help me. does it mean i square the value of net sales and then use HHI code?

[Nick Cox]

Squared sales make no sense. This is really a substantive issue: why are there are negative sales values in your dataset at all? How often do they arise in your data?

[Anuradha Saikia]

Hii Nick Cox Thank you for coming to the rescue again. The source from where I got the the data has negative values. This is net sales. Can I take only "sales" and not "net sales " in that case. Sales has no negative values..

[Jared Greathouse]

Stata isn't lying to you when she tells you there's negative values.

Regarding the output, show me the code you used which produced the error please as well as your example dataset.

As Nick says, you've likely got a data problem. Did you read the codebook associated with the dataset? Surely there's an explanation.

[Nick Cox]

Sales that are zero or positive are fine for this measure.

Net sales that can be negative I would say are not suitable for this. You need just any about other measure that works with negative and positive values, say SD or some interquantile range.

There could be literature on handling "sales" that are negative, but I don't know what it is.