A tale of two gravities

The flows of traded goods across countries are known to follow a gravity pattern: Their volumes are greater between countries that are larger in size and closer to each other. We find a similar pattern in the flows of territories across countries between 1870 and 2008. During this period, countries experienced inflows and outflows of territories, mirroring the international flows of goods. We find three other pieces of critical evidence supporting that the two flows interact through similar economic motives. Our findings illustrate the usefulness of international trade models for understanding international politics.