John Rawls' Theory of Justice holds that we should order a just society such that we would not know in advance what position we would be born into. This resonates intuitively. If you would be happy to come back in another life born into a random body, then you must believe that you either have a good chance of landing an acceptably fair share from the outset, or that you would be free to work your way up to a fair share from an average starting point.

The chances are that today you would be born into the 55% of population who are "miserable", earning less than $US 10k per annum, and could not work your way out of that cohort. Your chances of joining the cohort that hold nearly half of all wealth would be less than 1%.

I was born into the global middle class, the top 12%, and consider myself very fortunate. I certainly wouldn't want to roll the dice again in today's societies.