THE advocates of central planning and the supporters of free markets clash in nearly every field of public policy. But perhaps none of their confrontations is more emotionally based, or less useful for decision-making, than the current debate over blood policy. Emotionalism is inherent in the topic of the controversy. Blood is essential for life. It cannot yet be produced artificially. In order that some of those in need of transfusions may live, others must be persuaded to give their own blood. It is not surprising, then, that many would regard the systems by which blood donations are induced and blood transfusions paid for as symbolic of the bonds of community-or lack thereof-in modem society, and as having moral qualities few other human transactions could. Only the barrenness of the debate needs to be explained.