During the Song Dynasty (960—1279), China experienced unprecedented economic growth, with per-capita GDP increasing from $450 to $600 (in 1990 international dollars), according to estimates by Maddison. In sharp contrast, per-capita GDP remained more or less constant at $600 during the subsequent Ming-Qing period (1368—1911). This raises a major question in Chinese economic history: "Why did China’s early Industrial Revolution of the Song Dynasty give way to a stagnant agrarian economy during the Ming-Qing period?" I argue that a change in China’s provincial institutions in the 1370s, which weakened property right enforcement for commercial and industrial activities, accounts for this change in long-run economic performance.