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)
Law of demand higher price.Changes in demand is depicted graphically by a shift in the demand curve. On the other hand, "quantity demanded" refers to the quantity of goods consumers want for a given price, conditional on the other determinants. "Changes in quantity demanded" is depicted graphically by a movement along the demand curve. The law of demand was documented as early as 1892 by economist Alfred Marshall. Due to the law's general agreement with observation, economists have come to accept the validity of the law under most situations. Furthermore, researchers found that the success of the law of demand extends to animals