It would also mean that people could use this to say "All East Arbitaria people are less productive than all other ethnicities, therefore I shall ban them from my workplace. I am not anti-Arbitrian, I am just using the latest science". And of course these things are always statistical and so high performing East Arbitarians are going to be shut out of work because of this study.

The point is, there is a history of race-based discrimination in the world and researchers can't just pretend that it doesn't still exist when constructing these kinds of studies and how their outcomes could be used negatively by both benevolent and malevolent actors. It isn't just 'truth or not truth', also because lots of sociological studies aren't repeatable and many others suffer all sorts of issues with methods, populations, etc. Measuring people is crazy hard to do reliably. Anyway, my hot take is that its not a simple question and does not have a simple answer.