We know that some countries around the world are rich (e.g., the United State) and others are, relatively speaking, poor (such as Mexico). But not all poor countries are equally poor. Mexico, for instance, is pared to some African countries.

Knowing how to measure such differences can help us better grasp the relative well-being of people around the globe. In this video byMarginal Revolution University, economist Alex Tabarrok provides a simple tool paring relative wealth between nations.