Question

宏观经济学问题

Increases in government spending will lower the long-term growth rate of GDP if it lowers ________ spending, and the government purchases ________ goods and not ________ goods.

A net export spending; investment; consumption

B consumption; investment; consumption

C net export spending; consumption; investment

D investment; consumption; investment

Answer 1

政府购买为G，变化为△G，当政府购买增加△G时，意味着收入也增加了△G。收入的这一增加又使消费增加了边际消费倾向MPC×△G。消费的这次增加又一次增加了支出和收入。这第二轮增加的消费为MPC×（MPC×△G）。之后无限叠加下去。那么总收入的变化量△Y=（1+mpc+mpc2+mpc三次方+.......)△G △Y/△G=1+mpc+mpc2+mpc三次方+......，根据代数知识可换为△Y/△G=1/1-mpc。本题中mpc=0.9，那么△Y/△G=10，收入从5500到6000也就是△Y=500，带入△G=50，所以政府应支出50亿元。手写快痛苦死了，各种奇葩符号，求选最佳答案。