
Economists will often borrow theories and techniques, devised by other disciplines, to better advance their understanding of the world. One clear example of this is the so-called ‘gravity model of trade’. As physicists will tell you, Newton’s law of universal gravitation states that the gravitational pull exerted between two objects is proportional to the mass of each object, and it is inversely proportional to the distance between them. In turns out that something similar is true regarding the flow of global trade — the larger two economies are, and the shorter the distance between them, the more they tend to