Four things GDP per capita hides

GDP per capita divides a country's economic output by its population. It is a convenient shorthand for how rich a country is, and it is widely quoted. It is also an average, which means it hides things that matter.

1. Distribution. An average says nothing about how income is shared. Two countries with the same GDP per capita can have very different levels of inequality and poverty.

2. Unpaid work. Care for children and relatives, and housework, mostly fall outside the measure, though they are essential to well-being.

3. Prices and purchasing power. Currency conversion can mislead when comparing countries; adjusting for local prices gives a different picture.

4. Sustainability. Output that depletes natural resources or causes pollution can raise GDP today while reducing prospects tomorrow.

Limits: none of this makes GDP useless. It is a good measure of the size of market activity, and it correlates with many good outcomes.

A responsible reader treats GDP per capita as the starting point for a question, not its answer, and looks at poverty, inequality and health alongside it.