Laffer curve, the idea, popularized by economist Arthur Laffer and writer Jude Wanninski in the 1970s and '80s, is nothing more than a representation of the relationship between government revenue raised by taxation and all possible rates of taxation. In this curve the increasing tax rates beyond a certain point will become counterproductive for raising further tax revenue.
Click here to read an article from Dylan Matthew with tax experts giving their opinion for where the Laffer curve bends in U.S or in other words which is the revenue maximizing rate.
