【正文】 nd Curve Quantity of Output 0 Price Level 3. . . . which increases the quantity of goods and services demanded at a given price level. 2. . . . the equilibrium interest rate falls . . . 1. When the Fed increases the money supply . . . 圖 3. 貨幣注入 MS2 貨幣供給 MS 總需求 , A D Y Y P 在物價水平 P 時的貨幣需求 AD2 貨幣量 0 利率 r r2 (a) 貨幣市場 (b) 總需求曲線 產(chǎn)量 0 物價 水平 3. . . . 這增加了既定物價水平時的物品與勞務 的需求量。 2022 SouthWestern Changes in the Money Supply ? When the Fed increases the money supply, it lowers the interest rate and increases the quantity of goods and services demanded at any given price level, shifting aggregatedemand to the right. ? When the Fed contracts the money supply, it raises the interest rate and reduces the quantity of goods and services demanded at any given price level, shifting aggregatedemand to the left. Copyright 169。 ? 當美聯(lián)儲緊縮貨幣供給時，它提高了利率，并減少了任何一種既定物價水平時的物品與勞務需求量，使總需求曲線向左移動。 2022 SouthWestern The Role of InterestRate Targets in Fed Policy ? Moary policy can be described either in terms of the money supply or in terms of the interest rate. ? Changes in moary policy can be viewed either in terms of a changing target for the interest rate or in terms of a change in the money supply. ? A target for the federal funds rate affects the money market equilibrium, which influences aggregate demand. Copyright 169。 ? 既可以根據(jù)利率目標的變動，也可以根據(jù)貨幣供給的變動來說明貨幣政策的變動。 Copyright 169。 2022 SouthWestern 財政政策如何影響總需求 ? 財政政策 —— 對政府購買或稅收總水平的政府選擇。 ? 在短期中，財政政策主要影響物品與勞務的總需求。 2022 SouthWestern Changes in Government Purchases ? When policymakers change the money supply or taxes, the effect on aggregate demand is indirect— through the spending decisions of firms or households. ? When the government alters its own purchases of goods or services, it shifts the aggregatedemand curve directly. Copyright 169。 ? 當政府改變自己購買物品與勞務量時，它就直接地使總需求移動。 2022 SouthWestern Changes in Government Purchases 政府購買 ? There are two macroeconomic effects from the change in government purchases: 當政府購買變化時，有兩種宏觀經(jīng)濟效應： ? The multiplier effect 乘數(shù)效應 ? The crowdingout effect 擠出效應 Copyright 169。 2022 SouthWestern 乘數(shù)效應 ? 政府購買對總需求有一種 乘數(shù)效應。 Copyright 169。 Figure 4 The Multiplier Effect Quantity of Output Price Level 0 Aggregate demand, AD1 $20 billion AD2 AD3 1. An increase in government purchases of $20 billion initially increases aggregate demand by $20 billion . . . 2. . . . but the multiplier effect can amplify the shift in aggregate demand. 圖 4. 乘數(shù)效應 產(chǎn)量 物價 水平 0 總需求 AD1 200億美元 AD2 AD3 200億美元最初使總需求 增加 200億美元 …… 2……. 但乘數(shù)效應可 以擴大總需求的移動 Copyright 169。 2022 SouthWestern A Formula for the Spending Multiplier ? The formula for the multiplier is: Multiplier = 1/(1 MPC) ? An important number in this formula is the marginal propensity to consume (MPC). ? It is the fraction of extra ine that a household consumes rather than saves. Copyright 169。 ? 邊際消費傾向是家庭額外收入中用于消費而不用于儲蓄的比例。 2022 SouthWestern A Formula for the Spending Multiplier ? If the MPC is 3/4, then the multiplier will be: Multiplier = 1/(1 3/4) = 4 ? In this case, a $20 billion increase in government spending generates $80 billion of increased demand for goods and services. Copyright 169。 Copyright 169。 2022 SouthWestern 如何看待一國儲蓄與消費關(guān)系？ 節(jié)儉悖論：越節(jié)儉越貧窮（越儲蓄，儲蓄越少） 儲蓄多 —— 需求不足 —— 下一次產(chǎn)量減少 —— 收入減少 —— 儲蓄減少。 短期內(nèi)，儲蓄越少，產(chǎn)量越多。 如果投資充足，儲蓄越多對經(jīng)濟越有利 。 2022 SouthWestern The CrowdingOut Effect ? Fiscal policy may not affect the economy as strongly as predicted by the multiplier. ? An increase in government purchases causes the interest rate to rise. ? A higher interest rate reduces investment spending. Copyright 169。 ? 政府購買增加引起利率上升。 Copyright 169。 2022 SouthWestern 擠出效應 ? 擠出效應 —— 當擴張性財政政策引起利率上升，從而減少了投資支出時所引起的總需求減少。 Figure 5 The CrowdingOut Effect Quantity of Money Quantity fixed by the Fed 0 Interest Rate r Money demand, MD Money supply (a) The Money Market 3. . . . which increases the equilibrium interest rate . . . 2. . . . the increase in spending increases money demand . . . M D2 Quantity of Output 0 Price Level Aggregate demand, AD1 (b) The Shift in Aggregate Demand 4. . . . which in turn partly offsets the initial increase in aggregate demand. AD2 AD3 1. When an increase in governm