【正文】 。 ? 支持者認為，如果政府不作出反應，結(jié)果就是不合意的波動。 2022 SouthWestern 小結(jié) ? 由于貨幣與財政政策可以影響總需求，所以，政府有時用這些政策工具來努力穩(wěn)定經(jīng)濟。 Copyright 169。 ? 乘數(shù)效應傾向于擴大財政政策對總需求的影響。 2022 SouthWestern Summary ? When the government alters spending or taxes, the resulting shift in aggregate demand can be larger or smaller than the fiscal change. ? The multiplier effect tends to amplify the effects of fiscal policy on aggregate demand. ? The crowdingout effect tends to dampen the effects of fiscal policy on aggregate demand. Copyright 169。 ? 政府購買減少或增稅使總需求曲線向左移動。 2022 SouthWestern 小結(jié) ? 政策制定者可以用財政政策影響總需求。 Copyright 169。 ? 貨幣供給的增加最終導致總需求曲線向右移動。 2022 SouthWestern Summary ? Policymakers can influence aggregate demand with moary policy. ? An increase in the money supply will ultimately lead to the aggregatedemand curve shifting to the right. ? A decrease in the money supply will ultimately lead to the aggregatedemand curve shifting to the left. Copyright 169。 ? 向右下方傾斜的總需求曲線表現(xiàn)了物價水平與需求量之間的這種負相關(guān)關(guān)系。 2022 SouthWestern 小結(jié) ? 物價水平增加了貨幣需求，并提高了利率。 Copyright 169。 2022 SouthWestern 小結(jié) ? 凱恩斯提出了流動偏好理論來解釋利率的決定因素。△ TR 轉(zhuǎn)移支付乘數(shù) △ Y / △ TR = b /（ 1b） 結(jié)論：轉(zhuǎn)移支付與稅收的作用方向相反，程度相同 Copyright 169。 2022 SouthWestern 用 TR代表轉(zhuǎn)移支付，轉(zhuǎn)移支付通過影響可支配收入來影響支出。 ? 自動穩(wěn)定器包括稅制和一些政府支出 (轉(zhuǎn)移支付 )。 2022 SouthWestern Automatic Stabilizers ? Automatic stabilizers are changes in fiscal policy that stimulate aggregate demand when the economy goes into a recession without policymakers having to take any deliberate action. ? Automatic stabilizers include the tax system and some forms of government spending（Transfer payments). Copyright 169。 ? 他們建議讓經(jīng)濟靠自己的力量去克服短期波動。 2022 SouthWestern 反對積極穩(wěn)定政策論 ? 一些經(jīng)濟學家認為，貨幣和財政政策反而使經(jīng)濟更加不穩(wěn)定。 Copyright 169。 2022 SouthWestern 支持積極的穩(wěn)定政策 ? 就業(yè)法案有兩種含義 : ? 政府應該避免成為經(jīng)濟波動的原因。 Copyright 169。 Copyright 169。 所以，公債也不是凈財富 短見，不會意識到增稅。 即使增稅推遲，但關(guān)心后代的消費。 Copyright 169。 ? 這還取決于家庭對稅收變動是持久的還是暫時的感覺，因為居民是從長久來考慮消費決策的，把一生的收入分配到不同時期的消費中，盡可能使得消費平穩(wěn)。 2022 SouthWestern Changes in Taxes ? The size of the shift in aggregate demand resulting from a tax change is affected by the multiplier and crowdingout effects. ? It is also determined by the households’ perceptions about the permanency of the tax change. Copyright 169。稅收通過影響可支配收入來影響支出，在第一階段引起的支出變化小于稅收的變化。 2022 SouthWestern The key is: G is simply part of AD and Tax not. Taxes influence C indirectly, which is part of AD. Important assumption: tax is lumpsum tax, independent of output level. Copyright 169。 2022 SouthWestern The mechanism by which tax changes influence GDP Suppose tax rises by △ T, DI decreases by the same amount of △ T , which reduces AD by b △ T in the first round. △ T △ DI = △ T △ AD = b△ T GDP declines DI falls ……………… Copyright 169。 ? 家庭支出增加使總需求曲線向右移動。 ? 家庭把一部分額外的收入儲蓄起來。 2022 SouthWestern Changes in Taxes ? When the government cuts personal ine taxes, it increases households’ takehome pay. ? Households save some of this additional ine. ? Households also spend some of it on consumer goods. ? Increased household spending shifts the aggregatedemand curve to the right. Copyright 169。 2022 SouthWestern ΔY=ΔY1+ΔY2+ΔY3+ΔY4+….=Δ(1+MPC+MPC2+MPC3+…)=Δ/(1 MPC) Investment and consumption Output increased Period 1 ΔI=Δ ΔY1=Δ Period 2 ΔC2=MPC*ΔY1=MPC*Δ ΔY2=ΔC2=MPC*Δ Period 3 ΔC3=MPC*ΔY2=MPC2*Δ ΔY3=ΔC3=MPC2*Δ Period 4 ΔC4=MPC*ΔY3=MPC3*Δ ΔY4=ΔC4=MPC3*Δ …. …… ……. Copyright 169。 2022 SouthWestern The CrowdingOut Effect ? When the government increases its purchases by $20 billion, the aggregate demand for goods and services could rise by more or less than $20 billion, depending on whether the multiplier effect or the crowdingout effect is larger. Copyright 169。 AD2 AD3 總需求時 …… r2 200億美元 Copyright 169。 ? 擠出效應傾向于減弱財政政策對總需求的影響。 2022 SouthWestern The CrowdingOut Effect ? This reduction in demand that results when a fiscal expansion raises the interest rate is called the crowdingout effect. ? The crowdingout effect tends to dampen the effects of fiscal policy on aggregate demand. Copyright 169。 ? 較高的利率減少了投資支出。 2022 SouthWestern 擠出效應 ? 財政政策對經(jīng)濟的影響也許并不像乘數(shù)預測的那樣大。 Copyright 169。 長期內(nèi)，儲蓄越多，生產(chǎn)能力越大，增長越快。因此，節(jié)儉對個人是美德，對社會是不幸。 2022 SouthWestern ? 討論：節(jié)儉的悖論 ? 一個人節(jié)儉可以使一個人更富，一個國家所有的人都更節(jié)儉能不能使一個國家變富呢？ Copyright 169。 2022 SouthWestern 支出乘數(shù)的公式 ? 如果 MPC 是 3/4, 那么乘數(shù)是 : 乘數(shù) = 1/(1 3