Laffer curve costs). Although tax policy is often mentioned in relation to supply-side economics, supply-side economists are concerned with all impediments to the supply of goods and services and not just taxation. In their economics textbook "Principles of Economics" (7th edition), economists Karl E. Case of Wellesley College and Ray Fair of Yale University stated "The Laffer curve shows the relationship between tax rates and tax revenues. Supply-side economists use it to argue that it is possible to generate higher revenues by cutting tax rates, but evidence does not appear to support this. The lower tax rates by the Reagan administration decreased
To each according to his contribution concept also formed the basic definition of socialism for its pre-Marxist proponents, including Ricardian socialists, classical economists, and individualist anarchists. "To each according to his contribution" was a concept espoused by many members of the socialist and labor movement. Examples of this can be found from Ferdinand Lassalle's and Eugen Dühring's statements to Leon Trotsky's writings. However, it was Vladimir Lenin, inspired by Marx's writing on the subject in his "Critique of the Gotha Programme", who claimed the principle to be a fundamental element of socialism within Marxist theory. Libertarian socialist thinkers, such as American anarchist Benjamin Tucker, defined socialism