Laffer curve at an intermediate rate of taxation, and then falls again to zero revenue at a 100% tax rate. However, the shape of the curve is uncertain and disputed among economists. Under some assumptions, such as revenue being a continuous function of the rate of taxation, the maximum illustrated by the Laffer curve is a result of Rolle's theorem, which is a standard result in calculus. One implication of the Laffer curve is that reducing or increasing tax rates beyond a certain point is counter-productive for raising further tax revenue. A hypothetical Laffer curve for any given economy can only be
Notional election results local government wards, and it is the results from local government elections that are the primary source used to calculate notional results at a constituency level. Professors Colin Rallings and Michael Thrasher of Plymouth University have been involved in calculating notional results for general elections since 1992 where periodic boundary changes have taken place. The data compiled from their work has been used by several prominent media companies including television channels for the purposes of comparing one general election result to the last. Notional results have their limitations in that voting patterns may well have been different had new boundaries