Two hundred years ago, living standards in the richest and poorest parts of the world differed by a factor of a few; today the gap is fifty times or more. Explaining that divergence is the oldest question in economics, and two consecutive Nobel prizes, in 2024 for work on institutions and in 2025 for work on innovation-driven growth, put it back at the center of attention. Across ten modules and 40 sessions, this collection lays out the major schools side by side: growth theory, geography and disease, culture and trust, institutions, the developmental state, human capital and demography, and the long-cycle theories of rise and decline. Each theory is presented at its strongest, with its best evidence and its most serious critics, and all of them are then tested against the same country cases, from the two Koreas to Argentina, Botswana, the United States, and China. The aim is a reader who can hold several explanations at once, name the theory behind any claim about national success or decline, and judge that claim by its evidence rather than its conclusion.
