标题： 第一次自然地理与经济发展 显示英文标题

标题： A Perfect Storm: First-Nature Geography and Economic Development

摘要： 1825年，一场风暴在丹麦的林姆峡湾切出一条新航道，对原始自然地理造成了外生冲击。 双重差分估计显示，这条航道立即增加了贸易量，并在一代人时间内使人口增长了26.7%——相对于改善的市场准入，弹性为1.6。 新行业的高生育率和经济增长而非迁移推动了扩张。 一个对照实验——航道在约1086-1208年关闭——导致中世纪硬币和建筑发现数量对称下降，增强了外部有效性。 这些结果提供了首个稳健的因果证据，表明原始自然地貌塑造了经济活动的分布。 显示英文摘要

摘要： In 1825 a storm cut a new channel through Denmark's Limfjord, providing an exogenous shock to first-nature geography. Difference-in-differences estimates show the channel increased trade immediately and, within a generation, lifted population by 26.7 percent - an elasticity of 1.6 relative to the improved market access. Higher fertility and economic growth of new industries, not migration, drove the expansion. A mirror experiment - the waterway's closure circa 1086-1208 - caused symmetric declines in medieval coin and building finds, bolstering external validity. These results offer the first robust causal evidence that first-nature geomorphology shapes the location of economic activity.