Part 4 concludes The Architecture of Capital by examining when dependency stops looking cheap and optionality begins to carry a premium. Through Europe, the United States, China, and South Korea, it shows how capital architectures reveal their hidden liabilities under stress — and why strategic freedom depends on preserving alternatives before they are needed.

Five systems regenerate capital in five different ways. This essay compares the United States, Europe, Japan, South Korea, and China to show how allocation architecture determines what each system can finance, where dependency emerges, and ultimately who builds AI—and who rents it.

European household savings flow through institutions, regulation, tax policy, market structure, and default settings to become productive capital for innovation, industry, infrastructure, and long-term growth.