为什么各国人均收入差距如此悬殊？

KEY TAKEAWAYS

• Global income levels differ sharply, raising the question of why nations with access to similar technologies experience such wide gaps in economic outcomes.
• Research shows that differences in capital, skills, productivity, and economic and political institutions play important roles in shaping the variation of output and income across countries.
• Geography, natural resources and distinctive national policies can also influence income, though their effects vary widely and often interact with deeper structural factors.

Per capita income varies dramatically across countries, ranging from more than $100,000 in some small, very wealthy nations to less than $1,000 in the lowest income countries. Income can be measured in several ways, most commonly through gross domestic product (GDP) — the value of all goods and services produced in a country over a given period, typically a year. (See the first figure below.) A second measure is income that remains with domestic residents, i.e., gross national income (GNI). These income measures can be adjusted for differences in local prices (purchasing power parity, or PPP-adjusted) or left unadjusted. Regardless of the measurement approach, rich- and poor-country incomes differ enormously. Even seemingly similar countries, such as the United States and Canada, have fairly large differences in outcomes.

This raises a fundamental question: What creates such large income differences when practically every nation has access to nearly the same technology for producing goods and services?

SOURCE: International Monetary Fund.

NOTES: Data are for all countries in the IMF data with populations greater than 3 million; the 2026 forecast is the latest available year except for following countries: Afghanistan (2025); Lebanon (2025); Pakistan (2025) and Sri Lanka (2024). Data for China encompass mainland China.

The Role of Capital and Productivity

Production of goods and services requires both machines and a trained or educated workforce — that is, physical and human capital. The efficiency with which these resources are used, i.e., productivity, is equally important. In their 1999 paper, Robert Hall and Charles Jones demonstrated that differences in physical capital, human capital and productivity explain most of the variation in output per worker across countries.

Gary Becker argued that expected returns help determine how individuals and societies invest in education, training, health, and skills. That is, people invest in their own skills using the same economic logic with which they invest in physical capital. In their 1992 paper, N. Gregory Mankiw, David Romer and David Weil found that human capital importantly explains cross-country income variation.

Institutions and Economic Development

To create the conditions under which people and firms can invest in physical and human capital and use them efficiently, economies require institutions that protect property rights, establish rules for trading and contracts, and allow disputes to be settled peacefully. Douglass North, in his 1990 book, and Daron Acemoglu and James Robinson, in their 2012 book, detail how political and economic institutions create incentives for innovation and investment.

Trust, social cohesion and cultural attitudes toward work and innovation interact with such institutions to shape economic outcomes. In addition to these fundamental characteristics and institutions, fiscal, monetary and regulatory policies also influence business conditions. Poor monetary policy, for example, will likely leave a country less wealthy over time than if it had a well-managed central bank. Regulatory policies similarly influence investment in research, development and entrepreneurial activity.See Paul M. Romer’s 1990 article “Endogenous Technological Change” in the Journal of Political Economy.

Policy Debates and the Washington Consensus

In the 1990s, growth economists widely endorsed a package of economic reforms for developing nations known as the “Washington Consensus”: fiscal and monetary reforms, deregulation of prices and interest rates, and freer international trade and investment. Other economists criticized such growth recipes as insufficiently tailored to local circumstances and the particular problems in specific economies.See Dani Rodrik’s 2007 book One Economics, Many Recipes: Globalization, Institutions, and Economic Growth and his 2011 book The Globalization Paradox: Democracy and the Future of the World Economy.

Geography and Natural Resources

Geographic and other natural factors also influence wealth creation. For example, access to trade routes through ports or navigable rivers can be useful, as well as a suitable climate for habitation and agriculture.See Jeffrey D. Sachs’ 2005 book The End of Poverty: Economic Possibilities for Our Time.

Contrary to conventional wisdom, however, natural resources, such as large deposits of oil or minerals, are not systematically important for the vast majority of countries. Of course, natural resources contribute substantially to the income of countries with very generous endowments. For example, a generous oil and gas endowment makes the 2.98 million Qatari residents wealthy (on average) with recent per capita income of approximately $68,138. But natural resource endowments do not systematically enrich most countries, and they even may make them less rich than they would otherwise be.See Jeffrey D. Sachs and Andrew M. Warner’s 1995 working paper “Natural Resource Abundance and Economic Growth” and their 2001 paper “The Curse of Natural Resources” in the European Economic Review. This impoverishing effect might occur because natural resources induce people to compete to control the resources rather than focus on producing goods and services.See Halvor Mehlum, Karl Moene, and Ragnar Torvik’s 2006 article “Institutions and the Resource Curse” in The Economic Journal.

Special Cases

Three cases illustrate how special factors make wealthy countries even wealthier or at least offer the appearance of greater wealth.

Ireland’s tax policies have induced many corporations to establish their European headquarters there. These multinational corporations book profits in Ireland for tax purposes, which boosts Irish GDP substantially, but doesn’t reflect actual productive activity or directly benefit Irish residents, as seen by the large gap between that country’s nominal GDP per capita and GNI per capita in the figure and appendix below.

Norway's substantial petroleum reserves in the North Sea boost an already high per capita income. Unlike many resource-rich nations, Norway has prudently managed its oil wealth through a sovereign wealth fund — the Government Pension Fund Global. The government limits annual spending from the fund to approximately 3% of the fund’s value, effectively converting oil reserves into permanent wealth.

Finally, Switzerland’s political stability and history of respect for banking privacy have provided advantages in financial services, which make up 9% of Swiss GDP, a relatively large share.

SOURCES: International Monetary Fund and World Bank.

NOTES: Nominal GDP data are forecasted values for 2026, except for Afghanistan (2025), Lebanon (2025), Pakistan (2025) and Sri Lanka (2024). Purchasing power parity-adjusted GDP data are forecasted values for 2026, except for Afghanistan (2025), Lebanon (2025) and Sri Lanka (2024). Nominal GNI data are for 2025 except for Afghanistan (2024), Kuwait (2024), Lebanon (2024), Oman (2024), United Arab Emirates (2024) and Yemen (2018). Table comprises all countries in the data sources with populations greater than 3 million. Data for China encompasses mainland China. Also, see appendix below for data.

Conclusion

Physical and human capital, as well as productivity, explain most cross-country differences in income, though special factors are important for some countries. Understanding these variations requires examining not just the quantity of resources but also the institutional frameworks that determine incentives for effectively deploying those resources.

Notes

1. See Paul M. Romer’s 1990 article, “Endogenous Technological Change,” in the Journal of Political Economy.
2. See Dani Rodrik’s 2007 book, One Economics, Many Recipes: Globalization, Institutions, and Economic Growth, and his 2011 book, The Globalization Paradox: Democracy and the Future of the World Economy.
3. See Jeffrey D. Sachs’ 2005 book, The End of Poverty: Economic Possibilities for Our Time.
4. See Jeffrey D. Sachs and Andrew M. Warner’s 1995 working paper “Natural Resource Abundance and Economic Growth” and their 2001 article, “The Curse of Natural Resources,” in the European Economic Review.
5. See Halvor Mehlum, Karl Moene, and Ragnar Torvik’s 2006 article, “Institutions and the Resource Curse,” in The Economic Journal.