third root for negative values

[Benjamin Krüger]

Hey guys,

I have positive and negative values and a lot of outliers in my data. Therefore I decided to use a monotonic transformation. I wanted to use the third root because of the s-form of the function and I implemented it like this:

gen thsqrtNettovermögen_a = Nettovermögen_a^(1/3)

The problem is that stata only transformed the positive values and the negative values are simply missing and I don't understand why.

thanks in advance

Ben

[Felix Stips]

https://journals.sagepub.com/doi/pdf...867X1101100112

[Benjamin Krüger]

Thank you Felix, that was really interesting! I think I will export my data into excel, transform the data there and reimport it.

[Felix Stips]

Why not use the suggested workaround

sign(y) * abs(y)^(1/3)

?

[Nick Cox]

The main point behind the paper cited by Felix is that you really do not need to use Excel for this! It's one line in Stata:

 gen thsqrtNettovermögen_a = sign(Nettovermögen_a) * abs(Nettovermögen_a)^(1/3)

[Benjamin Krüger]

Ups I guess I missed the point. Thank you guys. I will use the workaroung