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)
Optimal foraging theory items that an animal should carry back to its nesting site or the optimal size of a food item that an animal should feed on. Figure 1, shows an example of how an optimal decision rule could be determined from a graphical model. The curve represents the energy gain per cost (E) for adopting foraging strategy x. Energy gain per cost is the currency being optimized. The constraints of the system determine the shape of this curve. The optimal decision rule (x*) is the strategy for which the currency, energy gain per costs, is the greatest. Optimal foraging models can