I don't see how acknowledging that economics is about choice excludes Marx at all, or limits methods of analysis, or social phenomena. Sorry to be empirical, but I would like to hear examples. Clearly, for instance, one element of choice is the institutional framework (whether cultural or legal) that a society chooses to impose upon itself (or has imposed upon it); that frames choice. You ignore it (as most economists in fact do) at your peril. Marx's cash nexus and his respect for the instinct of workmanship are also I think easily brought within the framework of understanding "choices." And if you are Weberian, you recognize that in traditional societies there is very little choice at the individual level. This is a much richer way, I think, of understanding the insights that economics offers than the very narrow focus on satisfying material wants, which is where most introductory texts begin (unfortunately). Fred Carstensen