Figure 1.

Prototypic behavioral economic demand and expenditure curves with the associated indices of relative value. Panel A depicts the demand curve and Panel B depicts the expenditure curve. Intensity of demand refers to consumption under conditions of zero or minimal cost; elasticity refers to the proportionate slope of either a portion or the overall demand curve; Breakpoint refers to the first price to suppress consumption to zero; O _max refers to the maximum total monetary allocation to consumption; P _max refers to the first price at which demand becomes elastic (i.e., decreases in consumption are proportionately greater than increases in price) and is also the price at which O _max is reached.