Martina Björkman Nyqvist, Lucia Corno, Damien de Walque, Jakob Svensson, 07 January 2017

Traditional HIV/AIDS education campaigns have not been completely effective in curtailing new infections. One potential reason behind this is that most of the infections occur among individuals who are willing to take risks when it comes to sexual behaviour, and campaigns have failed to specifically target these people. This column describes a new HIV intervention trialled in Lesotho that used a lottery to target such individuals and incentivise safer practices. HIV incidence was reduced by more than a fifth in treatment groups over the trial period. These results, combined with practical and cost advantages, suggest that such interventions could prove invaluable in the fight against HIV.

Michael Kremer, Christopher Snyder, Natalia Drozdoff, 29 January 2016

Many observers believe that pharmaceutical firms prefer to invest in drugs to treat diseases rather than vaccines. This column presents an economic rationale for why such a pattern may emerge for diseases like HIV/AIDS. The population risk of such diseases resembles a Zipf distribution, which makes the shape of the demand curve for a drug more conducive to revenue extraction than for a vaccine. Based on revenue calibrations using US data on HIV risk, the revenue from a drug is about four times greater.

Lucia Corno, Áureo De Paula, 13 January 2015

Addressing the HIV/AIDS epidemic requires an understanding of how risky sexual behaviours change over time. This column observes that, whereas the accuracy of self-reported data depends on the likelihood of people telling the truth, the likelihood of risky behaviours being detected in tests for sexually transmitted infections is equal to the disease transmission rate. Self-reported data may therefore be a more reliable measure of risky behaviours than the prevalence of sexually transmitted infections when the probability of transmission is low.

Esther Duflo, 20 April 2009

In Africa, where AIDS afflicts 22 million people, most religions promote abstinence and fidelity as the best way to stop the epidemic, especially among adolescents. This column describes two randomised experiments in Kenya showing that a general risk-avoidance message does not change behaviour, whereas a clear message on the relative risks of different sexual partners does.

Hendrik van Dalen, Mieke Reuser, 07 July 2008

Development assistance targeting health overwhelmingly concentrates on HIV/AIDS. This column argues that that focus neglects critical demographic issues and degrades health infrastructure, particularly in Sub-Saharan Africa. The prime rule for AIDS aid should be “First, do no harm”.