In the European Union Member States, value-added tax (VAT) is undergoing a continuous process of harmonization, which was initiated in the 1960s by the introduction of the First and Second Council Directives and which resulted in the implementation of the common tax assessment base. Currently, the European Union VAT system faces multiple challenges related in particular to the negative side effects of certain design features and progressing globalization. The main aim of this article is to discuss some dilemmas of the common VAT model. Particular attention is placed on the fiscal consequences of VAT preferences, as well as on the origins, components, and implications of the VAT gap. For the purpose of this analysis, 2 neighboring countries ...