Lomborg's Copenhagen Consensus Center has posed a challenging question: If we had an additional $50 billion to spend on mitigating global problems, how should we spend it? To suggest answers, the center convened a panel of eight distinguished economists to evaluate proposals by over two dozen specialists on problems ranging from AIDS and malnutrition to water shortage, civil war, climate change, and migration, among others. Their collective recommendation: focus on AIDS prevention, the provision of micronutrients to poor children, trade liberalization, and the control of malaria. Their choices were determined by the expected payoff, largely but not wholly in economic terms, that each of these programs could generate relative to its cost. Some issues, such as civil war, could not be evaluated in general terms and so were not ranked. The motivating principle of the exercise was that resources are limited, political leaders must make choices, and those choices should be governed by where the most good can be done for humanity -- especially for those who are so poor that they cannot look beyond where their next meal is coming from.