The main answer is that the standard model of tax evasion suggests that higher tax rates should lead to less tax evasion, and this result is often observed in theoretical models. However, studies using laboratory experiments typically find the opposite - that high tax rates are associated with greater tax evasion. One possible explanation for this result is that laboratory experiments often involve situations where participants are given a fixed amount of money to begin with, and the tax they are asked to pay is taken from this fixed amount. In this situation, high tax rates can lead to a perception of unfairness, which in turn may lead to greater levels of tax evasion. Another possible explanation is that laboratory experiments often involve simplified tax systems that do not reflect the complexity of real-world tax systems. As a conclusion, while the standard model of tax evasion suggests that higher tax rates should lead to less tax evasion, laboratory experiments often find the opposite. One possible explanation for this result is that laboratory experiments involve simplified tax systems and can create perceptions of unfairness, leading to greater levels of tax evasion.