Dear Statalist,

I got stuck with a surprising issue today when analyzing a dataset. I wanted to compute the kurtosis of the revenues of a company in the three years t0, t+1 and t+2. E.g. I wanted to compute a kurtosis value for the company Microsoft for the year 2000 -- which is based on Microsoft's sales values for the three years 2000, 2001 and 2002.

However, the weird thing that happens is that the result for the kurtosis is always 1.5
This is the case for all of the firms in my dataset, for all years

I assume this could have something to do with the specific formula for computing the kurtosis which Stata uses?

There appear to be different definitions and different ways how to compute the kurtosis. Would there by any alternative ways to compute the kurtosis? (So that the result is not always equal to 1.5)

It seems to me that the answer to this calculation is not necessarily always equal to 1.5 -- but it is rather a result of the specific definition used by Stata?

The current way I computed the kurtosis was as follows. If there would be any alternative suitable with regards to the above, this would be incredibly helpful.
My current Stata code is:
rangestat (kurtosis) firm_revenues, interval (Year 0 3) by(Company)

Thank you so much & all the best,
Franz