@cshentrup in something like the harsanyi thought experiment, i'll simply argue that as a normative matter, when we model policy, we should treat one another as having the same preference (over broad aggregates like money or access to health care, not over chocolate vs vanilla).

but that is an axiom. there's is no empirical data or fact about the world that justifies the choice. it is not "empirical". it simply reflects my (and i suspect your) egalitarian values. /fin