Muqaddimah empires to collapse, with the result that lower revenue was collected from high rates." He wrote: Ibn Khaldun introduced the concept now popularly known as the Laffer curve, that increases in tax rates initially increase tax revenues, but eventually the increases in tax rates cause a decrease in tax revenues. This occurs as too high a tax rate discourages producers in the economy. Ibn Khaldun used a dialectic approach to describe the sociological implications of tax choice (which now forms a part of economics theory): This analysis is very similar to the modern economic concept known as the Laffer curve.
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