2. Aggregation across consumers Can a society behave like a ration man? If a society behave like a ration man, can the utility of this"man" represented the Welfare of society? Aggregate demand:xpw…v)=∑x(p1) Wealth distribution w=(w,w,) And total wealth w=∑w2.Aggregation across consumers • Can a society behave like a ration man? • If a society behave like a ration man, can the utility of this “man” represented the welfare of society? • Aggregate demand: • Wealth distribution • And total wealth 1 1 ( , ) ( , ) I I i i i w w x w = x p p =  1 ( ) w = w wI 1 I i i w w = = 