How to Trade Goods When You Can't Use Money

stephen dubner: I began working on organ donation more than forty years ago. In 19 74, in volume one of the journal of mathematical economics, a herpscarf and lloyd shapley wrote an article about how to trade indivisible goods when you couldn't use money. This was a theoretical argument. It was entirely, entirely theoretical. And i thought, what an interesting problem to think about, how to trade without money.