Estimates of the changing equity characteristics of the US income tax withinternational conjectures

This article provides empirical estimates of the redistributive impact of U .S. personal income tar over the period 1979-1990. The estimates are based on tar return data compiled from the Ernst and Young/University of Michigan tar research database. The authors employ the Gini coefficient decompositi on methodology of Lambert and Aronson to distinguish between the vertical, horizontal, and reranking effects of the tar. The authors show growing pre- and posttax income inequality for the United States over the study period. But the data also suggest that the amount of horizontal inequity associate d with the U.S. personal income tar is relatively low. This article also co ntains some international comparisons. The redistribution associated with i ncome tares in the United Kingdom and Spain has been measured with the same methodology the authors employ. These two countries are also characterized by growing pre- and posttax inequality, although the level of inequality i s less there than in the United States. A final interesting point of compar ison, however is that the amount of horizontal inequity associated with the tar appears less than either in the United Kingdom or Spain.