Tax complexity indices and their relation with tax noncompliance: Empirical evidence from the Portuguese tax professionals

The important role played by Portuguese tax professionals in the tax system motive the analyses of their perception of tax complexity and its relation with their tax noncompliant behaviours. Data collected in 2013 by questionnaire allowed to perform it and this paper presents the results. Firstly, it analyses the main areas of tax complexity pointed out by tax professionals and secondly summarizes the fourteen areas of tax complexity, into three indices, by using the principal component analyses. Thus, an index of legislative tax complexity and two indices of administrative tax complexity (in professionals' and tax authority's context) were constructed. Data suggest that could be possible to measure the level of tax complexity by using indices. We verify that there is a relation between tax professionals' perceptions of tax complexity, measured through the indices, and some of their tax noncompliant behaviours, in particular the unintentional ones.