 Only wealthy countries have the financial and human resources to make sizable investments in biomedical research. Do these countries have obligations in justice to allocate resources to address the major health problems of the world’s poor? And finally, public health infrastructures in low-income countries struggle from shortages of health professionals, in part because of migration of professionals to wealthy countries. Is this a problem that health authorities in wealthy countries should work to contain, even as the health of their own populations benefit?