I can't. There's basically no theory behind the "Laffer curve." IIRC, it relies on two assumptions. Assumption #1: If the income tax rate is 0%, the government will collect zero income taxes. This assumption is basically a tautology. No one can disagree with it. Assumption #2: If the income tax rate is the maximum possible, 100%, the Laffer curve states that the government will collect zero income taxes, because taxpayers will find ways to avoid paying all taxes. This second assumption is... questionable, because taxpayers might successfully avoid paying only some taxes. Even if you agree with both assumptions, there's no agreement as to what tax rate would maximize government tax collections.