Volume 35, Number 1 (Winter) 2000
Osberg, Lars, and Kuan Xu. 2000. "International Comparisons of Poverty Intensity: Index
Decomposition and Bootstrap Inference." Journal of Human Resources
35(1):51-81.
This paper proposes an alternative formulation for the Sen-Shorrocks-Thon (SST) index of poverty intensity that is appropriate for survey data with sampling weights. It also decompose s the SST index into the poverty rate, the average poverty gap ratio among the poor, and the overall Gini index of poverty gap ratios. To account for sampling variation in estimates of poverty intensity, this paper uses the bootstrap method to compute confidence intervals and presents international comparisons using Luxembourg Income Study (LIS) data from the 1970s to the 1990s. Cross sectional and longitudinal analyses indicate that the percentage change in poverty intensity can be approximated by the sum of percentage changes in the poverty rate and average poverty gap ratio, since changes in the overall Gini index of poverty gap ratios are negligible. In the early 1970s poverty intensity in Canada and the United States was almost indistinguishable, but in the 1970s Canadian poverty intensity decreased. Large increases in poverty intensity occurred in the 1980s in the United States, the United Kingdom, and Sweden.
The authors are members of the Department of Economic s at Dalhousie University. This research was initially presented at the 51st Session of the International Statistical Institute, Istanbul, Turkey, August 22, 1997, Topic 72. The authors wish to thank the discussants at that session, two anonymous reviewers Georges Heinrich, and seminar participants at Dalhousie University, the University of New South Wales, and Sydney University for their comments. The authors wish to thank Lynn Lethbridge and Janice Yates for excellent research assistance and Monique Comeau, Heather Lennox, and Nancy Thibault for excellent secretarial assistance. They would also like to thank the Social Sciences and Humanities Research Council of Canada for its financial support under grant #410-93-0557 to Osberg. An earlier version of this paper was circulated as Luxembourg Income Study Working Paper 1 65, Ma y 1997 and Dalhousie Working Paper 97-03. The data/program used in this artic le can be obtained fro m April 2000 through June 2003 from Lars Osberg and Kuan Xu, Department of Economics, Dalhousie University, Halifax, Nova Scotia, CANADA B3H 3J5. E-mail: osberg@is.dal.ca and kxu@is.dal.ca.
© 2002 by the Board of Regents of the University of Wisconsin System
US ISSN 0022-166X