Q&A with Economist Jeffrey Sachs

Jeffrey Sachs is used to thinking big: His area of expertise is nothing less than our entire planet. As director of the Earth Institute at Columbia University, he worries about climatic changes that could have dire consequences for us all. As director of the United Nations' Millennium Project, he works to save billions of people from disease, hunger, and the other ravages of extreme poverty. And as a leading economist and a special adviser to the Secretary General of the United Nations, he has a unique appreciation of the monetary and political obstacles to tackling these global challenges. In February, at the annual meeting of the American Association for the Advancement of Science in St. Louis, he captivated the crowd with early results from a project in Africa that uses low-cost fertilizers and improved farming techniques to increase crop yields several times over. Sachs travels constantly, not just from country ...