World Tax Index: Methodology and Data

The article presents an indicator of tax burden that can be used as an alternative to tax quota, or implicit tax rates in macroeconomic analyses. It is called WTI – World Tax Index, which is an overall multi-criteria index that was constructed by authors on the basis of hard as well as soft data. The soft data expresses Qualified Expert Opinion that was gained through a large-scale questionnaire survey carried out among tax specialists from all OECD countries. The WTI consists of several sub-indices that deal with different groups of taxes, which are basically consistent with the classification according to the OECD. In the paper, values of WTI and its components for the period of 2005–2010 for all OECD countries are presented. Based on a comparison of the WTI with the tax quota, we found that the tax quota can be quite a good indicator of the real tax burden for some types of taxes. But we also show that the use of the tax quota for measuring the tax burden may be highly problematic in case of corporate taxation.