People need medications, but the poor often cannot afford them. Governments may not provide subsidies for health care and medications. Meanwhile, pharmaceutical firms focus their R&D on compounds likely to provide the best returns. What is the proper role of the following groups in addressing these ­dilemmas: national governments, branded pharmaceutical firms, and generic manufacturers?

Which (if any) of the following scenarios is the result of a natural monopoly? instructions: you may select more than one answer. a. patent holders of genetically modified seeds are permitted to sue farmers who save seeds from one planting season to the next. b. doctors in the united states are prohibited from practicing without a medical license. c. there is one train operator with service from baltimore to philadelphia. d. coal is used as the primary energy in a country with abundant coal deposits.