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
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