Laffer curve costs). Although tax policy is often mentioned in relation to supply-side economics, supply-side economists are concerned with all impediments to the supply of goods and services and not just taxation. In their economics textbook "Principles of Economics" (7th edition), economists Karl E. Case of Wellesley College and Ray Fair of Yale University stated "The Laffer curve shows the relationship between tax rates and tax revenues. Supply-side economists use it to argue that it is possible to generate higher revenues by cutting tax rates, but evidence does not appear to support this. The lower tax rates by the Reagan administration decreased
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