Yes, if you change the spaces of states and choices, maybe you can encode every possible agent as an utility function, not just those satisfying certain axioms of “rationality” (which I put in quotes because I don’t necessarily agree with them), but that would be to miss the entire point of expected utility theory, which is that it is supposed to be a theory of rationality, and is supposed to rule out irrational preferences. That means using state and choice spaces where those axiomatic constraints have real world meaning.
Tim and Tyrrell, do you know the axiomatic derivation of expected utility theory? If you haven’t read http://cepa.newschool.edu/het/essays/uncert/vnmaxioms.htm or something equivalent, please read it first.
Yes, if you change the spaces of states and choices, maybe you can encode every possible agent as an utility function, not just those satisfying certain axioms of “rationality” (which I put in quotes because I don’t necessarily agree with them), but that would be to miss the entire point of expected utility theory, which is that it is supposed to be a theory of rationality, and is supposed to rule out irrational preferences. That means using state and choice spaces where those axiomatic constraints have real world meaning.
Utility theory is bigger than the VN axioms. They are just one way of looking at things.