Last Monday The Wall Street Journal kicked off a debate on how best to allocate scarce resources to solve the world's problems. Bjorn Lomborg offered a summary of the latest findings from his Copenhagen Consensus project, where he has enlisted some of the world's top economists to address the issue. Over the next few Mondays we'll offer views on the subject from top political and business leaders. How would you spend $10 billion of American resources (either directly or through regulation) over the next four years to help improve the state of the world?

The...