經(jīng)濟波動導論最新課件

1、經(jīng)濟波動導論最新課件 第九章第九章 經(jīng)濟波動導論經(jīng)濟波動導論 宏觀經(jīng)濟學（第7版） （美） 曼 昆 經(jīng)濟波動導論最新課件 o本章從三個任務開始： o我們考察描述短期經(jīng)濟波動的數(shù)據(jù)； o討論經(jīng)濟的長期行為和短期行為之間的關鍵區(qū) 別； o引入總供給和總需求模型。 經(jīng)濟波動導論最新課件 o經(jīng)濟學家把產(chǎn)出與就業(yè)的短 期波動稱為經(jīng)濟周期，前面 的章節(jié)中我們建立了解釋經(jīng) 濟在長期中的行為的理論， 現(xiàn)在來看看經(jīng)濟學家如何解 釋短期經(jīng)濟波動。在思考之 前，我們首先看看描述短期 波動的一些事實。 經(jīng)濟波動導論最新課件 oGDP growth averages 33.5 percent per year over

2、 the long run with large fluctuations in the short run. oConsumption and investment fluctuate with GDP, but consumption tends to be less volatile and investment more volatile than GDP. 經(jīng)濟波動導論最新課件 Growth rates of real GDP, consumption Percent change from 4 quarters earlier Average growth rate Real GD

3、P growth rate Consumption growth rate 經(jīng)濟波動導論最新課件 Growth rates of real GDP, consumption, investment Percent change from 4 quarters earlier Investment growth rate Real GDP growth rate Consumption growth rate 經(jīng)濟波動導論最新課件 o經(jīng)濟周期不僅清楚反映在國民收入賬戶的數(shù)據(jù) 中，也反映在表示勞動市場狀況的數(shù)據(jù)中。 o失業(yè)率與GDP之間的這一負相關關系被稱為奧 肯定律。通過散點畫出的曲線告訴我們：

4、 oPercentage Change in Real GDP = 3.5% - 2 the Change in the Unemployment Rate 經(jīng)濟波動導論最新課件 失業(yè)率 Percent of labor force 經(jīng)濟波動導論最新課件 Okuns Law Percentage change in real GDP Change in unemployment rate 32 Y u Y 1975 1982 1991 2001 1984 1951 1966 2003 1987 2008 1971 經(jīng)濟波動導論最新課件 o許多經(jīng)濟學家都有著預測經(jīng)濟的短期波動的任 務，經(jīng)濟學家得

5、到預測結(jié)果的一種方法是觀察 領先指標，這些變量的波動往往先于整體經(jīng)濟。 o美國經(jīng)濟咨詢局一個私立經(jīng)濟研究機構(gòu)都 公布領先經(jīng)濟指標指數(shù)。 經(jīng)濟波動導論最新課件 oAverage workweek of production workers inmanufacturing oAverage initial weekly claims for unemployment insurance oNew orders for consumer goods and materials adjusted for inflation oNew orders, nondefense capital goods o

6、Vendor performance oNew building permits issued oIndex of stock prices oMoney-supply (M2) adjusted for inflation oInterest rate spread: the yield spread between 10-year Treasury onotes and 3-month treasury bills o10) Index of consumer expectations 經(jīng)濟波動導論最新課件 o短期和長期有什么不同 o長期： 價格是柔性，隨供需變化而變化 o短期： 在某一預

7、定水平上價格是“剛性（或粘性）” 的 當價格是粘性時，經(jīng)濟行為大不相同。當價格是粘性時，經(jīng)濟行為大不相同。 經(jīng)濟波動導論最新課件 P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD

8、 SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS P P Y Y LRASLRAS Y Y ADAD SRASSRAS 經(jīng)濟波動導論最新課件 o總需求曲線表示價格水平與需求產(chǎn)出量間的關 系。 o為了介紹本章的 AD/AS 模型，我們使用一個簡 單但不完全的基于貨幣數(shù)量論的總需求理論。 o第10-12 章，更詳細地發(fā)展了這個總需求理論。 經(jīng)濟波動導論

9、最新課件 o回憶第四章的數(shù)量方程： M M V V = P P Y Y 及其隱含的貨幣需求函數(shù)： (M M/P P )d = k k Y Y 這里這里 V V = 1/k k = 貨幣流通速度。 o對于給定的 M M 與 V V 值， 方程表明P P 、Y Y之間存 在負相關關系： 經(jīng)濟波動導論最新課件 Y P AD o價格水平的上 升導致實際貨幣 余額的下降 (M M/P P )， o導致對商品與 服務需求的下降。 經(jīng)濟波動導論最新課件 Think about the supply and demand for real money balances. If output is higher

10、, people engage in more transactions and need higher real balances M/P. For a fixed money supply M, higher real balances imply a lower price level. Conversely, if the price level is lower, real money balances are higher; the higher level of real balances allows a greater volume oftransactions, which

11、 means a greater quantity of output is demanded. 經(jīng)濟波動導論最新課件 Price level Output (Y) AD AD A decrease in the money supply M reduces the nominal value of output PY. For any given price level P, output Y is lower. Thus, a decrease in the money supply shifts the AD curve inward from AD to AD. 經(jīng)濟波動導論最新課件

12、Price level Output (Y) AD AD An increase in the money supply M raises the nominal value of output PY. For any given price level P, output Y is higher. Thus, an increase in the money supply shifts the AD curve outward from AD to AD. 經(jīng)濟波動導論最新課件 o回憶第三章： 在長期中，產(chǎn)出由生產(chǎn)要素的供給及技術狀 況決定： o充分就業(yè)時的產(chǎn)出并不依賴于價格水平， o因此，

13、長期總供給曲線(LRAS，the long run aggregate supply )是垂直的： ,()YFKL 經(jīng)濟波動導論最新課件 The vertical line suggests that changes in the price level will have no lasting impact on full employment. Y=F (K, L) 經(jīng)濟波動導論最新課件 Long-run effects of an increase in M Y P AD1 LRAS Y An increase in M shifts AD to the right. P1 P2 In

14、the long run, this raises the price level but leaves output the same. AD2 經(jīng)濟波動導論最新課件 o現(xiàn)實世界中，從短期看，許多價格是粘性的。 o既然這樣(從9-12章)， 在短期內(nèi)，我們假定所 有的價格水平都是預先給定的，是粘性的 o并且，廠商愿意供給在那樣的價格水平上的 消費者所能購買的數(shù)量 o因此，短期的總供給曲線(SRAS，short-run aggregate supply )是水平的： 經(jīng)濟波動導論最新課件 The short-run aggregate supply curve Y P P SRAS The S

15、RAS curve is horizontal: The price level is fixed at a predetermined level, and firms sell as much as buyers demand. 經(jīng)濟波動導論最新課件 Short-run effects of an increase in M Y P AD1 In the short run when prices are sticky, causes output to rise. P SRAS Y2Y1 AD2 an increase in aggregate demand 經(jīng)濟波動導論最新課件 YY

16、YY YY rise fall remain constant In the short-run equilibrium, if then over time, P will The adjustment of prices is what moves the economy to its long-run equilibrium. 經(jīng)濟波動導論最新課件 In the long run, the economy finds itself at the intersection of the long-run aggregate supply curve and aggregate demand

17、 curve. Because prices have adjusted to this level, the SRAS crosses this point as well. 經(jīng)濟波動導論最新課件 The economy begins in long-run equilibrium at point A. Then, a reduction in aggregate demand, perhaps caused by a decrease in the money supply M, moves the economy from point A to point B, where outpu

18、t is below its natural level. As prices fall, the economy recovers from the recession, moving from point B to point C. 經(jīng)濟波動導論最新課件 o經(jīng)濟學家把使總供給或總需求曲線移動的外生 事件稱為對經(jīng)濟的沖擊?？偣┙o與總需求模型 的一個目的是說明這些沖擊如何影響經(jīng)濟波動。 o這個模型的另一個目的是評價宏觀經(jīng)濟政策可 以如何對這些沖擊做出反應，這種政策也被稱 為穩(wěn)定化政策。 經(jīng)濟波動導論最新課件 The economy begins in long-run equilibrium

19、at point A. An increase in aggregate demand, due to an increase in the velocity of money, moves the economy from point A to point B, where output is above its natural level. As prices rise, output gradually returns to its natural rate, and the economy moves from point B to point C. 經(jīng)濟波動導論最新課件 oA sup

20、ply shock alters production costs, affects the prices that firms charge. (also called price shocks) oExamples of adverse supply shocks: nBad weather reduces crop yields, pushing up food prices. nWorkers unionize, negotiate wage increases. nNew environmental regulations require firms to reduce emissions. Firms charge higher prices to help cover the costs of compliance. oFavorable supply shocks low