In What’s Mine is Yours, Rachel Botsman argues for the spread of a “collaborative” form of this behavior to replace 20th-century individualistic forms. Interdependence inherent in this behavior is described by James Duesenberry’s “demonstration effect.” An intertemporal theory of this behavior was updated with discounted utility theory to form a “smoothing” effect in Franco Modigliani’s (*) life-cycle hypothesis. This behavior’s marginal propensity is subtracted from 1 (10[1])in formulas (-5[1])that calculate the fiscal multiplier. A variable that quantifies this behavior (-5[1])is typically the largest factor in calculating GDP and positively correlates with disposable income. A key (10[1])tenet in Keynesian economics (10[1])holds that governments can end recessions through this behavior’s “deficit” (10[1])type. For 10 points, name this variable often contrasted with saving. ■END■ (10[1])