Shermer speaks with political demographer, former demographics consultant to the United States Department of Defense, and author of The Future Faces of War, Jennifer Sciubba, about her new 8 Billion and Counting.

As the world nears 8 billion people, the countries that have led the global order since World War II are becoming the most aged societies in human history. At the same time, the world’s poorest and least powerful countries are suffocating under an imbalance of population and resources. In this conversation, based on her book 8 Billion and Counting, Jennifer Sciubba argues that the story of the twenty-first century is less a story about exponential population growth, as the previous century was, than it is a story about differential growth — marked by a stark divide between the world’s richest and poorest countries.

Drawing on decades of research and policy experience, Sciubba explains how demographic trends, like age structure and ethnic composition, are crucial signposts for future violence and peace, repression and democracy, poverty and prosperity. She explains the pitfalls of taking population numbers at face value and extrapolating from there, and argues that we must look at the forces in a society that amplify demographic trends and the forces that dilute them, particularly political institutions, or the rules of the game.