This study emphasizes the importance of defining the tax burden in terms of its compulsory, administrative, and fulfillment components in contrast to the general assessment method, which tends to focus only on the compulsory component. Although a compulsory burden is the main component of the economy’s tax burden, an evaluation of the other two components is also essential. Assessment of the compulsory burden using a new approach (according to aggregate investment expenditures) is the initial part of our tax burden research. In this study, a methodology for tax assessment based on the administrative and fulfillment burdens is developed. The qualitative indicators utilized in this research are proposed for calculation using the Mamdani fuzzy inference method. These qualitative indicators are considered in the estimation of the tax burden. The administrative and fulfillment burdens are assessed using the weighted sum model, which investigates this as a multi-criteria decision-making problem. This methodology is applied to assess the Azerbaijani tax system and the results obtained are compared with the Doing Business report 2019 (World Bank Group 2019). The results of this assessment can help inform the implementation of tax policy and thus improve the international ranking of the Azerbaijani government.

Keywords: tax burden; tax administration; tax liability fulfillment; fuzzy inference system; multi-criteria decision-making problem.