Since 1962, economists have used the "gravity equation" in international trade to explain empirically bilateral international trade flows, and have since more recently adopted the gravity model to explain foreign direct investment stocks. Motivated by its empirical success, Jeffrey H. Bergstrand provided one of the earliest formal theoretical foundations for the gravity equation in international trade in 1985. Since then, the gravity equation has become a fundamental element of international trade theory, empirical work, and policy analysis, especially of the effects of economic integration agreements and tariffs on trade flows and welfare. Understanding Globalization Through the Lens of Gravity is a curated collection of Bergstrand's published papers over the 30 years since his first paper on the theme of gravity. In four parts, the 17 papers span topics such as the determinants of international trade flows, economic determinants of free trade agreements, estimating the effects of economic integration agreements on trade flows, and economic determinants of multinational firms' foreign direct investment stocks, foreign affiliate sales and governments' bilateral investment treaties.