The Collier Report, for example, assumes that Britain's favourable balance on international trade in medical equipment reflects some desirable arrangement of economic resources, and that the existence of many similar versions of a piece of medical equipment is undesirable and reflects a misuse of resources: these views are debatable. Providing the NHS with the supplies it needs is only one of many examples of purchasing by public bodies from private manufacturers. Public purchasing raises many issues and it may be helpful to conclude the study of NHS supplies by placing it in the wider context of the relationship between the public and private sectors of the modern economy. Special problems exist over defence procurement for obvious reasons, and some extensive innovations have been introduced in recent years that could have lessons for public procurement as a whole. The rationalisation of the whole function of defence procurement was one of the government's intentions.