• Despite post-Monterrey donor initiatives, the Millennium Development Goals (MDGs) are underfinanced. • The revenue potential, the additionality and the speed of availability of new finance sources, and their political feasibility, are of particular importance. • On these criteria, it is unlikely that global taxes will be introduced in time. • The International Finance Facility, strengthened use of public guarantees and Global Premium Bonds, perhaps in combination, may stand a better chance of providing additional funds for the MDGs. • The most straightforward way to avoid underfunding of the Goals is to raise ODA further.