Laffer curve and possible differences in the incentive to work for different income groups complicate the task of estimation. The structure of the curve may also be changed by policy decisions. For example, if tax loopholes and tax shelters are made more readily available by legislation, the point at which revenue begins to decrease with increased taxation is likely to become lower. Laffer presented the curve as a pedagogical device to show that in some circumstances, a reduction in tax rates will actually increase government revenue and not need to be offset by decreased government spending or increased borrowing. For a reduction
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