Book excerpt: In this eye-opening work of economic theory, Jane Jacobs argues that it is cities—not nations—that are the drivers of wealth. Challenging centuries of economic orthodoxy, in Cities and the Wealth of Nations the beloved author contends that healthy cities are constantly evolving to replace imported goods with locally-produced alternatives, spurring a cycle of vibrant economic growth. Intelligently argued and drawing on examples from around the world and across the ages, here Jacobs radically changes the way we view our cities—and our entire economy.