Laffer curve New Palgrave Dictionary of Economics reports that a comparison of academic studies yields a range of revenue maximizing rates that centers around 70%. In the early 1980s, Edgar L. Feige and Robert T. McGee developed a macroeconomic model from which they derived a Laffer Curve. According to the model, the shape and position of the Laffer Curve depend upon the strength of supply side effects, the progressivity of the tax system and the size of the unobserved economy. Economist Paul Pecorino presented a model in 1995 that predicted the peak of the Laffer curve occurred at tax rates around 65%.
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