It is dangerous to believe that the end of AIDS is in sight. Around 30 million people around the world live with HIV, and another 30 million could become infected in the next decade if current trends persist. Billions of dollars have been spent on well-meaning attempts to save lives, with an alarming lack of high-quality evaluation of how these investments have performed.

This is true not only of abstinence campaigns, for which there is no evidence of effectiveness, but also for many other mainstays of the AIDS response. We do not know what works, where, and why, or how to replicate our successes.

For the project RethinkHIV, the Copenhagen Consensus Center and the Rush Foundation asked 30 of the world's top HIV economists, supported by epidemiologists, demographers, and medical professionals, to analyze the most promising responses to the epidemic in the world's worst-hit region, sub-Saharan Africa. They were asked to examine what could be achieved with extra investments in six key areas: prevention of sexual transmission, reduction of non-sexual transmission, treatment of AIDS patients, initiatives to use social policy and health-system strengthening to fight HIV/AIDS, and vaccine research.