Not really a useful concept since it’s purely subjective and may not meaningfully exist in any way at all.
Getting quantitative results is entirely useless if you don't want to think about the subjective qualitative reasons we thought some arbitrary metric might matter and how they might be limited. Having a high GDP or salary is about raising your quality of life and options. If you are actively prevented from living all sorts of other lives simply because they are not as profitable then you are poorer than the wild man.