Across the board, the post-2000 improvements in public health in sub-Saharan Africa have been dramatic, strongly supported by scaled-up aid. Up to 10 million HIV-infected individuals are now receiving life-saving, anti-retroviral medicines thanks at least in part to aid programs. Tuberculosis (TB) patients are being treated and cured, with a global TB mortality rate drop of 45 percent since 1990, and an estimated 22 million people alive due to TB care and control from 1995-2012, thanks to Global Fund support, which provides the lion’s share of donor financing to fight TB. With increased donor support, antenatal health visits, institutional deliveries, and access to emergency obstetrical care are all on the increase, contributing to a decline in sub-Saharan Africa’s maternal mortality rate (the annual number of female deaths per 100,000 live births) from 850 in 1990 to 740 in 2000 to 500 in 2010. Deaths of children under five worldwide have declined from 12.6 million a year in 1990 and 10.8 million in 2000 to 6.5 million in 2012.

These successes demonstrate a key lesson: that well-designed aid programs with sound operating principles, including clear goals, metrics, milestones, deliverables, and financing streams, can make an enormous difference, and that such programs should be devised and applied on a large scale in order to benefit as many people as possible. Such quality design needs to be based on the details of best practices, such as the combination of medicines, bed nets, and diagnostics used in cutting-edge, community-based malaria control. The economics profession needs to do a much better job working with experts in other fields, such as public health, in order to design effective aid interventions that reflect the nitty-gritty of high-quality systems delivery. While Prof. Easterly begrudgingly admits that some health aid programs have worked, for him this contradiction seems to make no difference to his overarching claim that aid is doomed to fail, for reasons that are hard to explain. All the evidence and all the exceptions have not mattered to his rhetoric, or for that matter, to his harsh attacks on me personally.