The concept of international or global (the terms tend to be used interchangeably) public goods is not as clearly defined as one would wish. There is now a large literature and while there is a broad consensus regarding what is at stake and what is being discussed, the nuances of writers differ. Many of the differences are essentially semantic, and should be dispelled at the outset. Each of the three words can be questioned. Does ‘international’ really have to mean that the benefits are completely global, in the sense that everybody on the globe benefits? In a broad sense yes, but in a narrow sense no. Almost everybody would agree that, for example, eradication of a disease (say malaria) is an international public good. In principle, everybody can benefit because the risk of contracting the disease is eliminated. In practice, one could identify many people for whom the initial risk of contracting the disease was effectively zero. They derive no discernible (or measurable) benefit, but the benefit exists nevertheless (the initial risk may have been imperceptible, but it was non-zero and is now zero). Thus, the benefit should be available to all even if some do not actually avail of the benefit. This relates to the willingness of beneficiaries (in this case the global public) to contribute to the cost of providing the public good.