IDEAS home Printed from
MyIDEAS: Login to save this paper or follow this series

The Disturbing "Rise" of Global Income Inequality

  • Xavier Sala-i-Martin

We use aggregate GDP data and within-country income shares for the period 1970-1998 to assign a level of income to each person in the world. We then estimate the gaussian kernel density function for the worldwide distribution of income. We compute world poverty rates by integrating the density function below the poverty lines. The $1/day poverty rate has fallen from 20% to 5% over the last twenty five years. The $2/day rate has fallen from 44% to 18%. There are between 300 and 500 million less poor people in 1998 than there were in the 70s. We estimate global income inequality using seven different popular indexes: the Gini coefficient, the variance of log-income, two of Atkinson's indexes, the Mean Logarithmic Deviation, the Theil index and the coefficient of variation. All indexes show a reduction in global income inequality between 1980 and 1998. We also find that most global disparities can be accounted for by across-country, not within- country, inequalities. Within-country disparities have increased slightly during the sample period, but not nearly enough to offset the substantial reduction in across-country disparities. The across-country reductions in inequality are driven mainly, but not fully, by the large growth rate of the incomes of the 1.2 billion Chinese citizens. Unless Africa starts growing in the near future, we project that income inequalities will start rising again. If Africa does not start growing, then China, India, the OECD and the rest of middle-income and rich countries diverge away from it, and global inequality will rise. Thus, the aggregate GDP growth of the African continent should be the priority of anyone concerned with increasing global income inequality.

If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.

File URL:
Download Restriction: no

Paper provided by National Bureau of Economic Research, Inc in its series NBER Working Papers with number 8904.

in new window

Date of creation: Apr 2002
Date of revision:
Handle: RePEc:nbr:nberwo:8904
Contact details of provider: Postal: National Bureau of Economic Research, 1050 Massachusetts Avenue Cambridge, MA 02138, U.S.A.
Phone: 617-868-3900
Web page:

More information through EDIRC

References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:

as in new window
  1. Schultz, T.P., 1998. "Inequality in the Distribution of Personal Income in the World: How It Is Changing and Why," Papers 784, Yale - Economic Growth Center.
  2. Ravallion, Martin & Shaohua Chen, 1996. "What can new survey data tell us about recent changes in distribution and poverty?," Policy Research Working Paper Series 1694, The World Bank.
  3. Quah, Danny, 1996. "Twin Peaks: Growth and Convergence in Models of Distribution Dynamics," CEPR Discussion Papers 1355, C.E.P.R. Discussion Papers.
  4. Andrea Brandolini & Anthony B. Atkinson, 2001. "Promise and Pitfalls in the Use of "Secondary" Data-Sets: Income Inequality in OECD Countries As a Case Study," Journal of Economic Literature, American Economic Association, vol. 39(3), pages 771-799, September.
  5. Ravallion, Martin & Datt, Gaurav & van de Walle, Dominique, 1991. "Quantifying Absolute Poverty in the Developing World," Review of Income and Wealth, International Association for Research in Income and Wealth, vol. 37(4), pages 345-61, December.
  6. T. Paul Schultz, 1998. "Inequality in the Distribution of Personal Income in the World: How it is Changing and Why," Working Papers 784, Economic Growth Center, Yale University.
  7. Bhagwati, Jagdish N, 1984. "Why Are Services Cheaper in the Poor Countries?," Economic Journal, Royal Economic Society, vol. 94(374), pages 279-86, June.
  8. Michael Kremer & Alexei Onatski & James Stock, 2001. "Searching for Prosperity," NBER Working Papers 8250, National Bureau of Economic Research, Inc.
  9. Steve Dowrick & Muhammad Akmal, 2005. "Contradictory Trends In Global Income Inequality: A Tale Of Two Biases ," Review of Income and Wealth, International Association for Research in Income and Wealth, vol. 51(2), pages 201-229, 06.
  10. Shorrocks, A F, 1980. "The Class of Additively Decomposable Inequality Measures," Econometrica, Econometric Society, vol. 48(3), pages 613-25, April.
  11. Klaus Deininger & Lyn Squire, 1996. "A New Data Set Measuring Income Inequality," CEMA Working Papers 512, China Economics and Management Academy, Central University of Finance and Economics.
  12. Hongyi Li & Lyn Squire & Tao Zhang & Heng-fu Zou, 1999. "A Data Set on Income Distribution," CEMA Working Papers 575, China Economics and Management Academy, Central University of Finance and Economics.
  13. Charles I. Jones, 1997. "On the Evolution of the World Income Distribution," Journal of Economic Perspectives, American Economic Association, vol. 11(3), pages 19-36, Summer.
  14. Pritchett, Lant, 1995. "Divergence, big time," Policy Research Working Paper Series 1522, The World Bank.
  15. Danny Quah, 1996. "Twin Peaks: Growth and Convergence in Models of Distribution Dynamics," CEP Discussion Papers dp0280, Centre for Economic Performance, LSE.
  16. Bourguignon, Francois, 1979. "Decomposable Income Inequality Measures," Econometrica, Econometric Society, vol. 47(4), pages 901-20, July.
  17. Grosh, Margaret E & Nafziger, E Wayne, 1986. "The Computation of World Income Distribution," Economic Development and Cultural Change, University of Chicago Press, vol. 34(2), pages 347-59, January.
Full references (including those not matched with items on IDEAS)

This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

When requesting a correction, please mention this item's handle: RePEc:nbr:nberwo:8904. See general information about how to correct material in RePEc.

For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: ()

If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

If references are entirely missing, you can add them using this form.

If the full references list an item that is present in RePEc, but the system did not link to it, you can help with this form.

If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your profile, as there may be some citations waiting for confirmation.

Please note that corrections may take a couple of weeks to filter through the various RePEc services.

This information is provided to you by IDEAS at the Research Division of the Federal Reserve Bank of St. Louis using RePEc data.