  Dworkin's approach begins with the idea that the measure of a resource that one person holds is what others would be willing to give up to get it. From this standpoint competitive market prices are the appropriate measure of the resources one possesses: In particular, the division of a lot of resources among a group of people is equal when all are given equal purchasing power for the occasion and all the resources are sold off in an auction in which no one's bids are final until no one wants to change her bids given the bids of the others.