Laffer curve tax structure in 1997. Some have also cited Hauser's Law, which postulates that US federal revenues, as a percentage of GDP, have remained stable at approximately 19.5% over the period 1950 to 2007 despite changes in marginal tax rates over the same period. Others however, have called Hauser's Law "misleading" and contend that tax changes have had large effects on tax revenues. More recently, based on Laffer curve arguments, Kansas Governor Sam Brownback greatly reduced state tax rates in 2012. The state, which had previously had a budget surplus, experienced a budget deficit of about $200 million in 2012. Drastic
Optimal foraging theory shown as a curve of energy gain per time spent in a patch (Figure 3). The curve starts off with a steep slope and gradually levels off as prey becomes harder to find. Another important cost to consider is the traveling time between different patches and the nesting site. An animal loses foraging time while it travels and expends energy through its locomotion. In this model, the currency being optimized is usually net energy gain per unit time. The constraints are the travel time and the shape of the curve of diminishing returns. Graphically, the currency (net energy gain per