Laffer curve as provided by supply-side economics. Although the simplified Laffer curve is usually illustrated as a straightforward symmetrical and continuous bell-shaped curve, when in reality the bell-shaped curve may be skewed or lop-sided to either side of the 'maximum' shown in the simplified version of the Laffer curve. Within the reality of complex and sudden changes to tax policy over time, the response of tax revenue to tax rates may vary dramatically and is not necessarily even continuous over time, when for example new legislation is enacted which abruptly changes tax revue expectations. Laffer explains the model in terms of two
Ibn Khaldun scholars is increasingly common. Influential British historian and international affairs specialist Arnold J. Toynbee has called Ibn Khaldun's Muqaddimah "the greatest work of its kind." Ernest Gellner, once a professor of philosophy and logic at the London School of Economics, considered Khaldun's definition of government the best in the history of political theory. More moderate views on the scope of Ibn Khaldun's contributions have emerged. Arthur Laffer, for whom the Laffer curve is named, acknowledged that Ibn Khaldun's ideas, as well as others, precede his own work on that curve. A focus on understanding the nuances of Ibn Khaldun's contributions