The advanced, industrialized nations of the world face common economic challenges, said Professor Joseph Stiglitz in a keynote address sponsored by Columbia Business School’s Center on Japanese Economy and Business. Speaking in Tokyo on March 21, Stiglitz, a Nobel laureate, professor of finance and economics, and the executive director of the Initiative for Policy Dialogue, listed global warming, aging populations, structural reforms, and growing inequality as concerns shared by Japan, Europe, and the United States.