武大宏观经济学期末考试卷答案.doc

武汉大学2010-2011学年第二学期期末考试 经济与管理学院 2010级 2011年6月29日 《宏观经济学》试题参考答案（A卷） (10 points) △GDP= $400 △NNP=△GDP-△depreciation=$400-$50=$350 △NI= △NNP - △sales taxes = $350 - $30 = $320 △PI= △NI -△ retained earnings = $320 - $100 = $220 △PDI= △PI-△personal income tax = $220 - $70 =$150 (10 points) To a macroeconomist, saving occurs when a person’s income exceeds his consumption, while investment occurs when a person or firm purchases new capital, such as a house or business equipment.. When your family takes out a mortgage and buys a new house, it is investment. When you use your $200 paycheck to buy stock in ATT, it is saving since your income of $200 is not being spent on consumption goods; but it is not investment because it does not form new capacity directly. The trade just means a change of ownership. When your roommate earns $100 and deposits it in her account at a bank, it is saving, because the money is not spent on consumption goods. When you borrow $1,000 from a bank to buy a car to use in your pizza-delivery business, it is investment since the car is a capital good. (10 points) All factors, that affect AD at a given price level, can be categorized to four groups according to which component of spending is most directly affect: (1)C, such as a tax cut/hike, a stock market boom/decline; (2) I, such as optimism/pessimism about the future, a fall/rise in interest rates due to an increase/decrease in money supply; (3)G, such as greater/smaller spending on defense or highway construction, (4)NX, such as a boom/recession overseas, an exchange-rate depreciation/appreciation. According to the production factors, the long-run AS may change arising from the following four sources which affect the natural rate of output: (1)K (physical capital or human capital ), such as the increase of the number of machines or that of college degrees;(2)L, such as an increase in immigration from abroad, the change of the natural rate of unemployment due to increasing minimum wage