Tax compliance under horizontal and vertical equity conditions. An experimental approach

Tax compliance is a complex phenomenon, which requires to be addressed from different perspectives. We report the results of a real-effort experiment aiming at testing the effect of different equity conditions on individual tax compliance levels. We show that equity considerations seem to change individual behaviour only when a vertically unfair tax system is implemented. Also, random effects Tobit estimations show that being audited in the previous period has a negative effect on tax evasion, whereas the level of the fine paid in the previous period positively affects income underreporting. Also, we find that when subjects are in the vertical inequity condition they are significantly more likely to fully evade taxes than in the equity condition, whereas such result cannot be found in the horizontal inequity condition. Finally, we find a standard gender effect showing that female participants are less likely to evade taxes than man and that risk aversion negatively affect tax evasion behaviour.