What makes an argument or an explanation an “economics” argument , and “economics” explanation? Doug claims it – economics – has to incorporate the concept of greed. Greed is maximisation – or is it? John challenges Doug’s views here . Aren’t greedy people cold, calculating, grabbing, narcissistic……well, all the bad stuff? The answer, for Doug, is that greed and maximisation – people do the best they can with what they’ve got – are one and the same. Someone with what we’d all call nice friendly cooperative other regarding objectives or preferences is greedy, just as someone with sicko, evil , nasty sadistic or masochistic preferences – self or other regarding – can also be greedy. Hmmm. Subtle stuff here: the tradeoffs in a set of preferences are NOT the same thing as the maximisation process that is directed at improving these objectives. That maximisation process is what Doug means by greed, not the content of the objectives. Oh, and by the way, the basic modelling assumption of greed or self interest is used to explain behaviour, not judge it or condone it. That’s an important distinction we take up later when we discuss positive and normative.