Not too long ago, lots of people were convinced the world was becoming overpopulated. This idea was promoted in TV shows, movies, and books, and discussed at parties and other social events. But conversations these days are headed in a totally different direction: The world is becoming depopulated. Which view is correct? This is not just an academic question, because the answer will shape foreign policy, social programs, and both national and local budgets. Are you ready for the dramatic changes coming our way?