As biomedical technology has expanded, the quantity of resources has increased, and scarce resources have become scarcer. Expensive equipment, medicine, artificial organs, blood for the treatment of hemophilia, donors for organ transplant operations, and research facilities are all in limited supply. Often when research presents us with a new technology, we find ourselves uncertain whether to fund its application and, if so, how extensively to produce it. One problem is economic: how are these resources to be most efficiently provided? How can more people be helped, and how can costs be reduced? Other problems are ethical: by what principles, procedures, and policies can justice in the production and distribution of resources best be ensured? There is thus both an economic dimension and an ethical dimension to these problems, which I shall refer to, in general, as problems of macro-allocation.