... GDP. 30 PRINCIPLES OF ECONOMICS is largely determined by personal income, incometaxes, consumer expectations, consumer indebted-ness, wealth, and price level. Since consumption isimpossible ... billion; for consumption function CЉthere is less saving at each level of disposable income than there is forconsumption function CЈ. 38 PRINCIPLES OF ECONOMICS aggregate demand or aggregate supply? ... and aggregate demand remains at ADЈ, 28 PRINCIPLES OF ECONOMICS cession and the beginning of economic recovery.The time span between troughs and peaks is classi-fied as an expansionary period (trough...