Empirical research in international economics is characterized by a tight link between economic theory and econometric specifications. The course will introduce the structural approach to empirical research using the gravity model of international trade, which is the workhorse model in empirical trade research. Based on a theoretical derivation of the model, students will learn both how to estimate the corresponding structural econometric model and how to use the model to perform counterfactual policy analyses. Using the trade gravity expression as a starting point, closely related models for example for international migration, FDI flows, or carbon emissions embodied in international trade will also be considered.