INDICES OF TAX PROGRESSIVITY AND MACROECONOMIC VARIABLES IN THE U.K. 1960-2001

This paper has two goals. First it determines the respective impacts of variations in the tax rates and in the distribution of pre-tax incomes on changes in tax progressivity in the United Kingdom during the period 1960-2001. Second it checks whether macroeconomic variables or the political cycle influenced the degree of tax progressivity. The results of the empirical analysis show that the significant decrease in tax progressivity observed between 1960 and 1982 was essentially the result of a variation in the distribution of pre-tax incomes. During the later period (1982-2001) the data indicate that there was no significant change in overall progressivity and in the components of its change. The second part of this study indicates that in the long run both inflation and unemployment negatively affect tax progressivity. The impact of the political cycle on tax progressivity is not clear and the results depend on the tax progressivity index that is used. It is interesting to note that in the cases where a political effect is found it indicates that under the Labour party, tax progressivity increased, for a given level of inflation and unemployment. The econometric analysis also shows that in the short run, only unemployment has a significant effect on tax progressivity.