Thirdly, the narrowly defined goals and measurability of outcomes of trust funded projects make them attractive to donors.6 Trust funds for communicable disease control have increasingly dominated the bank’s trust fund portfolio over the past 15 years (figs 1 and 2).5 12 Some private donors to these funds—particularly the Gates Foundation—have strong preferences for financing technological and disease specific interventions.24 25 The outcomes of these grants are usually measured by simple metrics, like the number of bed nets, vaccines, or drug tablets distributed in specific countries.26 27 Furthermore, because public and private donors to trust funds are often able to earmark their commitments to specific regions or activities, they are able to trace what their aid is buying at the country level.6