PPP-based national accounts have become an important part of the database for macroeconomists, development economists, and economic historians. Frequently used global data come from the Penn World Table (PWT) and the World Bank's World Development Indicators; a substantial fraction of the world...

People in poor countries live shorter lives than people in rich countries so that, if we scale income by some index of health, there is more inequality in the world than if we consider income alone. Such international inequalities in life expectancy decreased for many years after 1945, and the...