The 'Laffer Curve' is conceptually related to the debate on:

The Laffer Curve is an illustration of the hypothetical relationship between tax rates and total tax revenue collected by the government. It suggests that at a 0% tax rate, revenue is zero. As rates rise, revenue increases. However, beyond a certain optimal point, very high tax rates discourage work, investment, and compliance (leading to tax evasion). This disincentive effect can shrink the tax base (total income/activity being taxed) so much that further increases in the tax rate actually led to a decrease in total tax revenue. It is central to debates about the revenue effects of tax cuts.