As mentioned, WTI Consulting Software (WTICS) is a specialized map with expert content that shows the level of tax burden in each member country of the Organization for Economic Co-operation and Development (OECD). The tax burden is measured here by a unique, trademark protected World Tax Index (WTI). It is a multi-criteria index, which is further broken down into lower-level sub-indices, each of which is again composed of several sub-parts so as to capture the maximum possible variables that have an impact on the tax burden. It is therefore not just a representation of tax rates – the WTI index and its parts also address issues of tax progression, deductible items, tax incentives or the much-discussed issue of administrative complexity of taxation.

WTI is composed of the following subindexes:

• Personal Income Tax (PIT)
• Corporate Income Tax (CIT)
• Value Added Tax (VAT)
• Other Taxes on Consumption (OTC)
• Property Tax (PRO)

WTI and its components are dimensionless indicators that range from 0 to 1, and the closer the value is to one, the greater the relevant tax burden. Values are comparable in time and space.

In the map, which is available to users on the Application tab, there are data on the tax burden in the specified breakdown, ie. on the WTI and its individual components, available for OECD member countries and for different periods. The users can thus map different combinations of individual types of taxation, years and countries according to their current interest.

In the database, which is available to users on the Data tab, all data that are displayed on the map are then available. This database can be used mainly by researchers for the needs of analyzes performed in the framework of basic and applied research.

Details of the methodology for calculating the WTI indicator and its sub-indices are also available in the paper by members of the research team entitled WORLD TAX INDEX: METHODOLOGY CHANGES AND REVISION OF DATA FOR OECD COUNTRIES FROM 2000 TO 2018.