Measuring tax effort in developing countries

The traditional methodology, as established by the International Monetary Fund, for measuring tax effort over time and in relation to estimated taxable capacity, is based on the tax ratio. The objects of the article are: (a) to demonstrate that government policy can not be deduced from the buoyancy of tax revenue as reflected in the observed rates of growth or relative magnitudes of the tax ratio; and (b) to propose an alternative measure based directly on policy determined discretionary changes in tax structures, with which the IMF taxable capacity measure, correctly interpreted, could be complementary.