Laffer curve D. Rockefeller and Henry Ford. While he served as Secretary of the U.S. Treasury Department his wealth peaked at around US$300–US$400 million. Personal income-tax receipts rose from US$719 million in 1921 to over US$1 billion in 1929, an average increase of 4.2% per year over an 8-year period, which supporters attribute to the rate cut. David Hume also expressed similar arguments in his essay "Of Taxes" in 1756, as did fellow Scottish economist Adam Smith, twenty years later. The Democratic party made a similar argument in the 1880s when high revenue from import tariffs raised during the Civil War (1861–1865)
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