The great expansion of economic activity since the end of World War II has caused an unprecedented rise in living standards, but it has also caused rapid changes in earth systems. Nearly all types of natural capital-the world's stock of resources and services provided by nature-are in decline....

How rich would resource-abundant countries be if they had actually followed the Hartwick Rule (invest resource rents in other assets) over the past 30 years? The authors use time series data on investments and rents on exhaustible resource extraction for 70 countries to answer this question. The...