Optimal tax in his article titled "Using Elasticities to Derive Optimal Income Tax Rates" derives a formula for optimal level of income tax using the both compensated and uncompensated elasticities. Saez writes the tradeoff between equity and efficiency is a central consideration of optimal taxation, and implementing a progressive tax allows the government to reallocate their resources where they are needed most. However, this deters those of higher income levels to work at their optimal level. Saez decomposes the marginal effects of a tax change into mechanical, behavioural and welfare effects, as follows: The sum of these effects should be zero at
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