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)
Keeling Curve Keeling Curve The Keeling Curve is a graph of the accumulation of carbon dioxide in the Earth's atmosphere based on continuous measurements taken at the Mauna Loa Observatory on the island of Hawaii from 1958 to the present day. The curve is named for the scientist Charles David Keeling, who started the monitoring program and supervised it until his death in 2005. Keeling's measurements showed the first significant evidence of rapidly increasing carbon dioxide levels in the atmosphere. According to Dr Naomi Oreskes, Professor of History of Science at Harvard University, the Keeling curve is one of the most important