Powerful currents have reshaped the structure of families over the last century. There has been (i) a dramatic drop in fertility and greater parental investment in children; (ii) a rise in married female labor-force participation; (iii) a significant decline in marriage and a rise in divorce; (iv)...

I use a randomized experiment to test whether information can change sexual behavior among teenagers in Kenya. Providing information on the relative risk of HIV infection by partner's age led to a 28% decrease in teen pregnancy, an objective proxy for the incidence of unprotected sex....

The response of sexual behavior to HIV in Africa is an important input to predicting the path of the epidemic and to focusing prevention efforts. Existing estimates suggest limited behavioral response, but fail to take into account possible differences across individuals. A simple model of...

We evaluate the consequences of prosecuting HIV+ people who expose others to the risk of infection. We show that the effect of aggressive prosecutions on the spread of HIV is a priori ambiguous. Aggressive prosecutions tax risky behavior and thus deter unsafe sex and limit the number of sexual...

Recent breakthroughs in the treatment of HIV have coincided with an increase in infection rates and an eventual slowing of reductions in HIV mortality. These trends may be causally related, if treatment improves the health and functional status of HIV+ individuals and allows them to engage in...

Increased HIV risk creates incentives for people with low sexual activity to reduce their activity, but may make high-activity people fatalistic, leading them to reduce their activity only slightly, or actually increase it. If high-activity people reduce their activity by a smaller proportion...