STATISTICAL ANALYSIS OF WORLD INCOME DISTRIBUTION

Research Project

Project/Area Number	12630032
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Economic statistics
Research Institution	OKAYAMA UNIVERSITY
Principal Investigator	YOSHIDA Tateo Okayama University, Faculty of Economics, Professor, 経済学部, 教授 (00150889)
Project Period (FY)	2000 – 2001
Project Status	Completed (Fiscal Year 2001)
Budget Amount *help	¥1,600,000 (Direct Cost: ¥1,600,000) Fiscal Year 2001: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 2000: ¥1,100,000 (Direct Cost: ¥1,100,000)
Keywords	World Income Distribution / Global Income Distribution / Inequality / Lorenz Curve / Gini Coefficient / Entropy Measure / Purchasing Power Parity / 所得分布 / 不平等度 / 集中度曲線 / RAI指数 / 中間主義的不平等
Research Abstract	This study examines the levels and trends in the inequality of worldwide income distribution during the second half of the 20th century. Using aggregate GDP data from the latest version of the Penn World Table (PWT6.1) provided by A. Heston, R. Summers and B. Aten, and income distribution data from the World Income Inequality Database Ver 1.0 (WIID Ver1.0) compiled by UNDP and UNU/WIDER, we construct the world distribution of real income for 115 countries between 1962 and 2000, and calculate the Gini coefficient and the gereralized entropy class of inequality implied by the world distribution. Our new evidence shows that world income inequality increased from 1962 to 1980 and decreased during the 1980's and 1990's. However, if China is excluded from the sample, all of the inequality measures document the increasing inequality in the world distribution of income over the past 30 years ; this suggests that the rapid growth of per capita income in China was the main factor in the recent trend towards decreasing world income inequality.