While the additionality of resources is ambiguous, we can answer a closely related issue definitively. Resources being used for the provision of GPGs in the area of health R&D and communicable disease control come from traditional, not innovative, sources. The typical new initiative depends on a philanthropic institution for its start-up, followed by infusions of government support channelled through bilateral aid organizations [15] . Yet, the GPG concept is firmly rooted in the self-interested use of domestic monies and as such sees funding as distinct from current aid and philanthropic flows. While there have been innovative fund raising suggestions ranging from a tax on airline travel to a global lottery, progress has been slow. In the health field, Advance Purchase Commitments and the "front-loading" of international assistance for immunization via the GAVI Alliance's International Finance Facility) represent steps forward [22] . In the first case, donors pre-commit to vaccine purchases if R&D is successful; in the second, future aid commitments are collateralized so that funds can be raised immediately in the international bond markets. These are welcome innovations, but they still tap the same source: international donor agency budgets.