Among major countries, the United States leads the world in one measure of national wealth, per capita GDP (gross domestic product). This measure is a crude one, since it simply divides the size of the economy by the size of the population; by no means should one infer from this measure that every man, woman, and child collects this amount each year from the government. However, it is a crude way of adjusting the size of a country's economy for the size of its population, since larger countries will - all things being equal - have larger economies. By this measure, the United States was most recently #1 in the world.

The per capita GDP also gives an upper limit to the average income a citizen of a country could enjoy. In a utopian world in which 100% of the GDP were somehow distributed equally to all citizens, for example, China could not have an average income of more than about $3,600 a year unless it grows its economy.