Optimal tax the optimum. Stipulating this condition results in the following formula for the optimal top tax rate, if incomes are Pareto distributed: formula_1 where: Empirical estimation of the parameters of this equation suggests that the revenue-maximising top tax rate is between approximately 50% and 80%, although this estimate neglects long-run behavioural responses, which would imply higher elasticities and a lower optimal tax rate. Saez's analysis can also be generalised to tax rates other than the top rate. In the late 1970s, Arthur Laffer developed the Laffer curve, which demonstrates that there are two effects of changing tax rates: an arithmetic effect—if
Laffer curve Jude Wanniski, who was also present at the meeting. The basic concept was not new; Laffer himself notes antecedents in the writings of the 14th-century social philosopher Ibn Khaldun and others. Laffer does not claim to have invented the concept; he notes that there are antecedents, including in the "Muqaddimah" by 14th-century Tunisian scholar Ibn Khaldun, and in the writings of John Maynard Keynes. It was not until the 1970s that Laffer's name began to be associated with the idea. The term "Laffer curve" was reportedly coined by Jude Wanniski (a writer for "The Wall Street Journal") after a 1974