In this paper, we investigate the relationship between globalization and income inequality over time. We employ three globalization indices, including GlobalIndex, KOF-Index, and a composite globalization index generated from factor analysis to implement the empirical tests in the use of the panel threshold regression model. Our empirical results show the tests for single threshold model in the cases of taking GlobalIndex and KOF-Index as the threshold variable are both highly significant. It implies the effect of globalization on income inequality differs depending on the degree of globalization in a country. In the initial stage of globalization, globalization raises the income inequality in a country. When the degree of globalization is over a critical value, the rate of rising income inequality may have the tendency to slow down.

References:
Andersen, Torben M. and Herbertsson, Tryggvi Thor (2005), “Quantifying Globalization”, Applied Economics, 37:10, pp. 1089-1098.
Bhagwati, Jagdish (2000), “Globalization and Appropriate Governance”, WIDER Annual Lecture 4, UNU/WIDER.
Birdsall, Nancy (2000), “Why Inequality Matters: The Developing and Transitional Economies”, Conference on The World Economy in the 21st Century: Challenges and Opportunities.
Bobek, Vito and Vide, Romana Korez (2005), “The Signification and the Feasibility of Measuring Globalization of Economy”, Industrial Management & Data Systems Vol. 105, No.5, pp. 596-612.
Chen, Shaohua and Ravallion, Martin (2004), “How Have the World's Poorest Fared since the Early 1980s?”, World Bank Research Observer, Vol. 19, No. 2, pp. 141-169, Fall 2004 Available at SSRN.
Cornia, Giovanni Andrea and Court, Julius (2001), “Inequality, Growth and Poverty in the Era of Liberalization and Globalization”, WIDER Policy Brief 4, UNU/WIDER.
Dollar, David (1992), “Outward-Oriented Developing Countries Really Do Grow More Rapidly: Evidence from 95 LDCs, 1976-85”, Economic Development and Cultural Change, April, pp. 523-544.
Dollar, David and Kraay, Aart (2001), “Trade, Growth, and Poverty”, World Bank Discussion Paper, Development Research Group, The World Bank, Washington, DC.
Dollar, David (2005), “Globalization, Poverty, and Inequality since 1980”, Oxford University Press on behalf of the International Bank for Reconstruction and Development, The World Bank, 20, pp. 145-175.
Dreher, Axel (2006), “Does Globalization Affect Growth? Evidence from a new Index of Globalization”, Applied Economics 38, 10: 1091-1110.
Dreher, Axel; Gaston, Noel and Martens, Pim (2008), “Measuring Globalization - Gauging its Consequences”, New York: Springer.
Edwards, Sebastian (1992), “Trade Orientation, Distortions, and Growth in Developing Countries”, Journal of Development Economics 39(1), pp. 31-57.
Firebaugh, G. and B. Goesling (2004), “Accounting for the Recent Decline in Global Income Inequality”, American Journal of Sociology 110, pp.283-312.
Foreign Policy (2001), “Measuring Globalization”, Foreign Policy, No. 122, pp.56-65.
Foreign Policy (2007), “The Globalization Index 2007”, Foreign Policy, http://www.foreignpolicy.com/story/cms.php?story_id=3995&print=1.
Freeman, Richard B. (1995), “Are your wages set in Beijing”, Journal of Economic Perspectives, Vol. 9, No. 3, pp. 15-32.
Hansen, Bruce E. (1996), “Inference when a nuisance parameter is not identified under the null hypothesis”, Econometrica 64, pp. 413-430.
Hansen, Bruce E. (1999), “Threshold Effects in Non-Dynamic Panels: Estimation, Testing, and Inference”, Journal of Econometrics 93, pp. 345-368.
Harris, Richard G. (1993), “Globalization, Trade, and Income”, The Canadian Journal of Economics/Revue canadienne d’Economique, Vol. 26, No. 4, pp. 755-776.
Harrison, Bennett and Bluestone, Barry (1988), “The Great U-Turn: Corporate Restructuring and the Polarizing of America”, New York, Basic Books.
Heshmati, Almas (2003), “Measurement of a Multidimentional Index of Globalization and its Impact on Income Inequality”, Discussion Paper No. 2003/69, UNU/WIDER.
James, Jeffrey (2002), “Technology, Globalisation and Poverty”, Edward Elgar.
Kaus, Mickey (1992), “The End of Equality”, A New Republic Book, New York: HarperCollins, Basic Books, ISBN 0-465-09814-2.
Krugman, Paul and Venables, Anthony J. (1995), “Globalization and the Inequality of Nations”, The Quarterly Journal of Economics, Vol. 110, No. 4, pp. 857-880.
Kuznets, Simon (1953), “Shares of Upper Income Groups in Income and Savings”, New York, National Bureau of Economic Research.
Lindert, Peter H. and Williamson, Jeffrey G. (2001), “Does Globalization Make the World More Unequal?”, NBER Globalization in Historical Perspective Conference in Santa Barbara, California.
Lockwood, Ben and Redoano, Michela (2005), “The CSGR Globalisation Index: an Introductory Guide”, Centre for the Study of Globalisation and Regionalisation Working Paper 155/04.
Lundberg, M. and Squire L. (2003), “The simultaneous Evolution of Growth and Inequality”, The Economic Journal, 113 (487), pp. 326–344.
Mahler, Vincent A. (2004), “Economic Globalization, Domestic Politics, and Income Inequality in the Developed Countries: A Cross-National Study”, Comparative Political Studies, 37, 1025.
Manasse, Paolo and Turrini, Alessandro (2001), “Trade, Wages, and ‘Superstars’”, Journal of International Economics 54, pp. 97–117.
Martens, Pim and Zywietz, Daniel (2006), “Rethinking Globalization: A Modified Globalization Index”, Journal of International Development 18, pp. 331-350.
Milanovic, Branko (2003), “Can We Discern the Effects of Globalization on Income Distribution? Evidence from Household Surveys”, World Bank Policy Research Paper 2876, Washington DC. World Bank.
O'Rourke, Kevin H. (2001), “Globalization and Inequality: Historical Trends”, CEPR Discussion Paper No. 2865. Available at SSRN: http://ssrn.com/abstract=277292
Pearson K. (1901), “On Lines and Planes of Closest Fit to Systems of Points in Space”, Philosophical Magazine 2: 559-572.
Putko, Colonel Michele (2006), “Defining and Quantifying Globalization”, U.S. Army War College Strategy Research Project.
Raab, Marcel, Ruland, Michael, Schönberger, Benno, Blossfeld, Hans-Peter and Hofäcker, Dirk (2007), “GlobalIndex-A Multidimensional Approach to Globalization Measurement”, TransEurope Project, http://www.transeurope-project.org.
Randolph, J. (2001), “G-Index: Globalisation Measured”, World Markets Research Center, http://www.globalinsight.com.
Sachs, Jeffrey D. and Warner, Andrew (1995), “Economic Reform and the Process of Global Integration”, Brookings Papers on Economic Activity, (1), pp. 1-118.
Spearman, Charles Edward (1927), “The Abilities of Man: Their Nature and Measurement”, The Macmillan Company, New York.
Stiglitz, Joseph E. (2003), “Globalization and Growth in Emerging Markets and the New Economy”, Journal of Policy Modeling 25, pp. 505–524.
Wade, Robert Hunter (2001), “Is Globalization Making World Income Distribution More Equal?”, Working Paper Series No.01-10, LSE Development Studies Institute.
Wade, Robert Hunter (2004), “Is Globalization Reducing Poverty and Inequality?”, World Development Vol. 32, No. 4, pp. 567-589.
Williamson, Jeffrey G. (1997), “Globalization and Inequality, Past and Present”, The World Bank Research Observer, Vol. 12, No. 2, pp. 117-35.