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.

Yi Huang, Jianjun Miao, Pengfei Wang, 08 November 2016

The Chinese Shanghai Stock Exchange Composite Index dropped by a third in mid-2015, wiping out billions in share value. One of the responses of the Chinese government was to directly participate in the stock market. This column assesses the costs and benefits of this intervention, finding that the resulting gains amounted to about 5% of Chinese GDP. The value was created not just from increased equity and investor confidence, but also from increased liquidity and reduced probability of default for listed firms.