Tax fraud and counterfeiting activities raise concern among governments, international organizations, media and academic researchers. Related efficiency issues and equity implications are of paramount importance because such illegal activities reduce public revenues, create inefficiency in resources allocation, and affect the individual income distribution. Because of such relevant effects, a natural question arises on which factors are likely to determine and motivate individuals' tax compliance or engagement in illicit activities. Traditionally, tax compliance has been dealt with as a decision-making problem of rational individuals under uncertainty, often affected by the presence of social norms and by other more conventional supply and demand factors. We shall afford this issue, by also complementing it by an in-depth analysis of the role played by equity considerations. One of the goals of this project is to contribute to the public and scientific debate on tax compliance by studying motivations related to fairness and equality of opportunity theory, neglected so far by the literature. The project is composed of three parts. The first part is devoted to theoretical and empirical/experimental analyses of some intertwined aspects related to the issue of tax fraud, the infringement of regulatory burdens on labour market and trade in counterfeit products. The second part aims at understanding whether fairness considerations might be listed amongst the determinants of tax evasion and counterfeiting activities. The third part is devoted to the analysis of the redistributive effects and distributional implications of such phenomena.