Implicit rate of municipal and agglomeration taxation

The Walloon municipalities, like all the Belgian municipalities and the Brussels agglomeration, may establish, and all have established, a tax additional to the tax on natural persons. This tax is applied as a percentage, called ‘additional percentages’, of the personal income tax due to the State. All residents of the municipality who are liable for personal income tax are also liable for that municipal tax, which is added to it and collected at the same time. Each municipality fixes each year the rate of its "additional cents". The implicit rate of taxation, for one municipality or, at another level of aggregation, several municipalities, is equal to the ratio between the additional municipal tax(s) and the personal tax due to the State. It is this rate, comparable between municipalities and levels, that is chosen as the key indicator. The secondary indicator is the average implicit tax rate per municipality (total tax, including the additional tax/total taxable net income).