This book explains how, and why, economics has been applied to a terrible pandemic, using a range of examples mostly drawn from the region most affected, sub-Saharan Africa. Part I shows that microeconomic approaches have found fertile ground in a public health approach that 'blames' individual choices for HIV transmission. Despite their attractiveness, however, these approaches fail to explain contemporary patterns of HIV prevalence, illustrating the importance of factors that are excluded from the standard micro-economic approach. Part II of the book looks at our problems in understanding the economic impact of AIDS, and explains why economists cannot agree if epidemic disease is a good or bad thing for economic development. In both sections of the book, the potential for alternative approaches is shown, and the book ends by arguing that a political economy approach can bring meaningful insights to our understanding of the spread and impact of HIV/AIDS.