1、0/57,Chapter 17Inflation and Price Level 通貨膨脹與物價水準,1/57,學習目標,1. Explain how the Consumer Price Index is constructed and use it to calculate the inflation rate解釋CPI如何估計,用以計算通貨膨脹率2. Show how the CPI is used eliminate the effects of inflation in economic data如何以CPI進行平減4. Discuss the two most important
2、biases in the CPICPI兩個主要的估計偏誤原因5. Distinguish between inflation and relative price changes to find the true cost of inflation通貨膨脹與相對價格變動6. Understand the connections among inflation, nominal interest rates, and real interest rates實質利率的算法,2/57,Cover story,Prices of goods change over timeAdjust values
3、, incomes, or spending for change in pricesConstant purchasing powerBaseball salariesBabe Ruth earned $80,000 in 1930超過當時的 Hoover 總統Barry Bonds earned $10.3 million in 2001超過當時的 Bush 總統但是,哪一個情況比較好?誰的購買力比較高?Inflation increases uncertainty when planning for the future 通貨膨脹帶來不確定性Consider costs of infla
4、tion 通貨膨脹的成本,3/57,台北排名44 生活費比韓港星低 2011-08-18 中國時報 林上祚台北報導,4/57,Problems of Inflation物價膨脹的問題,Makes comparisons of economic conditions over time difficult跨時比較的困難Creates uncertainty about the futureHow much should I save for retirement?未來的不確定性增加Imposes many costs on an economy增加許多成本(例如鋼鐵價格、油價),5/57,物價上
5、漲衝擊九成三民眾生活 縮衣節食少娛樂 【中時電子報林淑玲台北報導】2007.05.21,民眾對於民生用品物價上漲，對生活的衝擊造成非常嚴重的有三成，六成多民眾表示有影響，但可以接受。若進一步觀察物價上漲對於食、衣、住、行、育、樂六大基本民生生活必須項目，所造成的衝擊，46.5的受訪民眾表示最無法忍受食方面的上漲，是六大項裡比例最高者。其次，則是行的部分，被36.5的民眾列為最無法忍受的上漲項目。至於衣、住、育、樂，則僅分別有6.1、6.3、3.2、1.5的民眾，認為是無法接受的漲價項目。顯示出，物價上漲讓每日都得有支出開銷的食與行，對民眾荷包壓力最大。,6/57,Measuring Infla
6、tion 衡量物價膨脹,Consumer Price Index (CPI) is a measure of changes in prices Consumer Price Index, CPI消費者物價指數CPI measuresThe cost of a standard basket of goods and services in a given year Relative to the cost of the same basket of goods and services in the base year相同的一籃標準財貨之成本,目前相對於基期的水準The fixed year
7、 is called the base year基期Base year changes periodicallyIt uses a constant basket of goods and servicesIt is collected by the Bureau of Labor Statistics台灣的物價指數由行政院主計處三局三科製作 (見國內商品行情表),7/57,國內商品行情,8/57,95年基期消費者物價指數(CPI)查價項目、權數及商品性質別 (請見Excel表),Table 17.1, 17.2, Calculating the CPI,相同的一籃財貨組合，不同年度的購買成本
8、這個算法和實質 GDP 有何異同,Calculating the CPI 消費者物價指數的計算,CPI is the ratio of the cost of the basket of goods in current year to the cost in the base yearBase year cost $6802005 cost $850CPI = (850 / 680) (100) = 1.25兩年度的一籃財貨成本相除，其比例變化就是物價變化率Cost of living in 2005 is 25% higher than in 2000CPI for the base ye
9、ar is always 1 基期都是100%CPI for a given period is the cost of living in that period relative to what it was in the base yearBEA uses CPI as a percentage the ratio times 100,11/57,CPI消費者物價指數,Measures changes in prices of a typical market basket標準的市場一籃物品Is used to eliminate the effects of inflation fro
10、m economic dataCPI 可用來排除物價波動帶來的效果,12/57,Price Index 價格指數,A price index measures the average price of a given class of good or services relative to the price of the same goods and services in a base year 各種價格指數的概念都相同，皆是在相同的財貨組成前提下，當期和基期購置成本的差異，以此計算物價變動CPI measures the change in consumer pricesOther i
11、ndicesCore inflation is CPI without energy and food 核心物價膨脹率Producer price index 生產者物價指數Import / export price index 進出口物價指數Whole sale price index 躉售物價指數,Inflation rate 通貨膨脹率,The rate of inflation is the annual percentage change in the price level物價指數的年度變動率Inflation in 2004(1.889 1.840) / 1.840= 0.027
12、 = 2.7%Inflation in Great DepressionPeriod of falling output and prices, deflation Inflation rates are negative經濟蕭條，通貨緊縮,14/57,Figure 17.1 美國的通貨膨脹率,15/57,台灣的物價膨脹率 (inflation rates),16/57,Adjusting for Inflation物價膨脹的調整,A nominal quantity is measured in terms of its current dollar value名目數量是當期物價計算A re
13、al quantity is measured in physical terms 實質數量是實體計算To compare values over time, use real quantities 要進行跨時比較，需要實質數量Deflating a nominal quantity converts it to a real quantityDivide a nominal quantity by its price index to express the quantity in real terms名目數量透過物價指數平減，可得出實質數量,Table 17.3 Family Income
14、 in 2000 and 2005,Can a family buy more with $20,000 in income in 2000 or with $22,000 in 2005?2000 is the base year for the CPI, 基期Deflate nominal income in both years to get real income平減名目成為實質Compare real income比較實質所得的高低$20,000 in 2000 has the greater purchasing power,Page 495, Baseball Stars比較棒球
15、明星實質所得,Compare Babe Ruths salary with Barry BondssRequires a CPI series that includes 1930CPI using 1982 1984 as base year 基期Bonds had higher real salary，是Bush 總統的25倍Does not convey information about relative incomes1930 was Great Depression Multi-million dollar salaries common for sports stars in 2
16、001,Real Wages 實質工資,Real wage is the purchasing power of workers nominal wages 實質工資是受雇員工名目工資的實質購買力The real wage for any given period is calculated by dividing the nominal wage by the CPI for that period以CPI 平減名目工資，即為實質工資US production worker wagesCPI uses 1982 1984 as base yearReal wages were higher
17、in 1970,20/57,Figure 17.2 Nominal and real wages,21/57,台灣男性實質工資 (2001=100),22/57,Indexing 工資指數化,Indexing increases a nominal quantity each period by the percentage increase in a specified price indexIndexing prevents the purchasing power of the nominal quantity from being eroded by inflation工資和物價指數連
18、動，可避免物價膨脹帶來的購買力縮減Indexing automatically adjusts certain values, such as Social Security payments, by the amount of inflation 社會安全給付和物價有指數化關係If prices increase 3% in a given year, the Social Security recipients receive 3% moreNo action by Congress required 內建的政策機制，不需每次透過議會決定Indexing is sometimes incl
19、uded in labor contracts部份勞動契約加入指數化條款,Adjusting for Inflation 工資的指數化,An indexed labor contractFirst year wage is $12 per hourReal wages rise by 2% per year for next 2 yearsRelevant price index is 1.00 in first year, 1.05 in the second, and 1.10 in the thirdNominal wage is real wage times the price in
20、dex各年度的實質所得皆上升,24/57,Minimum Wage最低工資,Congress sets the national minimum wage in nominal terms最低工資是名目的Publicized debate results in periodic increasesIndexing would be simpler and less controversialPoliticians appear to benefit from the debate最低工資是資方和勞方拉鋸的結果，也是政客藉以牟利的工具Minimum wage increased 15 times
21、 between 1970 and 2008Real minimum wage has decreased by about one-third in that period但是實質最低工資卻在同一時段下降最新基本工資於2010年9月13日審議通過，為每月新台幣17880元，每小時新台幣98元，2011年1月1日正式實施。,25/57,舊版課本 Example 19.4, Real wage of US production worker,Compare the real wage of 1970 and 1990Wage in 1970 = $3.23/hour, 1990=$10.01/h
22、ourCPI in 1970 is 0.388 and in 1990, 1.307 1982-84 as base yearIn real term, 1970= 3.23/0.388 = $8.32 1990= 10.01/1.307 =$7.66實質工資的比較,1990甚至低於1970,26/57,Accuracy of CPI精確性,Changes in the CPI are importantDirectly impacts government budgets影響聯邦政府的福利制度和最低工資Boskin Commission 1996 (headed by Michael Bos
23、kin,老布希總統的經濟顧問) study shows CPI overstates inflation between 1 - 2% a year高估 (1-2個百分點)Costing federal government billions of dollars more than necessary every yearUnderestimating of true living standard低估真正的生活水準Suppose CPI indicates 3% inflation when cost of living actually increases 2%Real income i
24、ncreases 1% CPI高估造成生活水準低估,27/57,Reasons for Overstatement of Inflation物價膨脹高估的理由,Quality adjustment bias品質調整的偏誤: statistics do not account for the fact thatThe quality of goods and services change over time品質改善新電腦價格高,功能強(就像較大的pizza價格較高)New goods appear新東西出現,缺乏基期物價比較Substitution bias替代的偏誤CPI uses a fi
25、xed market basket以固定的一籃衡量Consumers seek out cheaper substitutes when prices rise消費者尋求便宜的替代品,P463, CPI Biases 消費者物價指數的偏誤,CPI uses a fixed basket of goods and servicesWhen the price of a good increases, consumers buy less and substitute other goodsFailing to account for substitution overstates inflati
26、onExample: base year cost of market basket,CPI Substitution Bias 替代效果的偏誤,In 2005, coffee and scones are more expensiveBuying exactly the same basket of goods costs $300, compared to $200 in 2000CPI = 300 / 200 = 1.50,CPI Substitution Bias 替代效果的偏誤,Actually, consumer substitutes tea for coffee,都買茶而不買咖
27、啡Scones purchases constantTrue CPI for consumer is 250 / 200 = 1.25CPI estimate of 1.50 is 20% higher than the consumers experience 忽略替代效果,造成估計偏誤,31/57,Price Level vs. Relative Price價格水準與相對價格,Price level價格水準是全體的物價水平A measure of the overall level of prices at a particular point in time as measured by
28、 a price index such as the CPIRelative price相對價格是各種財貨間的相對物價The price of a specific good or service in comparison to the prices of other goods and servicesIf the price of oil decreases by 10% and all other prices decrease by 3%, then the relative price of oil decreases (i.e. oil is cheaper relatively
29、)Suppose we have a one-time doubling of the gas priceOverall price level and inflation increase by a small amountThe increase in the relative price of gasoline is large油價突然上漲兩倍，物價水準不會上漲兩倍，但汽油和其他財貨的相對物價會有大幅改變,Relative Prices相對價格的變化,Relative prices can change markedly without corresponding changes in
30、inflation物價水準可能不變，但相對物價有很多改變Summer prices 夏天的價格Government rarely attempts to manage relative pricesAffect the supply and demand for that industry台灣政府有時候干預物價 (近期的凍漲、緩漲或減稅)Inflation is affected by macroeconomic policy物價膨脹受到總體政策的影響,33/57,The cost of inflation: not what you think,Price levelRelative pri
31、ce兩者的概念有所差異某些財貨的物價上升，並不一定會帶來物價水準上升及通貨膨脹，因為有些物價下跌可能抵銷如果所有的物價(包括工資)都上升10%,則通貨膨脹對於購買力不會有影響,34/57,The cost of inflation: not what you think,Prices transmit information about 1. The cost of production and 2. The value buyers place on buying an additional unit同時帶來供需雙方的訊息Inflation creates static in the com
32、munication物價膨脹對供需雙方的溝通帶來阻礙Buyers and sellers cant easily tell whetherThe relative price of this good is increasing ORInflation is increasing the price of this good and all others不易確認物價變動的來源Deciding these issues requires market participants gather information at a costResponse to changing prices is t
33、entative and slow供需雙方對物價變動的反應遲疑且緩慢想像現在的狀況，如果是做生意或持家，如何考慮,35/57,36/57,政府喊漲 消費意願創歷史新低油電雙漲最衝擊弱勢2012年6月號遠見雜誌,2012年4月1日起，中油將所有油品每公升調高超過3元，漲幅超過10兩週後，經濟部又宣布5月中將大漲電價，平均漲幅逼近30 油電乃民生必需，價格影響社會甚劇。該讓人民免於恐懼的政府這次帶頭喊漲，一時間成本被整體推升，萬物喊漲，通膨帶來的各種恐慌、憂慮甚囂塵上。,37/57,Indexing Avoids Distortions租稅指數化避免扭曲,Income taxes have bee
34、n indexed to avoid bracket creep 所得賦稅級距的攀升Bracket creep occurs when a household is moved into a higher tax bracket due to increases in nominal but not real incomeHigher tax brackets have a higher tax rateIndexing income taxes matches tax rates to the real income levelSuppose the tax rate on $50,000
35、is 25% in 2000CPI is 1 for 2000, 1.25 for 2005Nominal income of $62,500 is taxed 25% in 2005又稱為 inflation tax, 通貨膨脹稅,38/57,Costs of Inflation物價膨脹的成本,Reduces efficiency of the economy降低效率“Shoe-leather” costs磨鞋跟成本 (how is plastic money?)More frequent trips to the bankInflation raises the cost of holdi
36、ng cash現金持有成本提高“Noise” in the price system價格體系的噪音Difficult to interpret information conveyed by pricesRelative price change or inflation?Distortions of the tax system扭曲租稅系統Many provisions in the tax codes are not indexedCauses bracket creep適用稅率區間悄然上升Causes paying more than initially intended付更多租稅Inf
37、lation tax:通貨膨脹稅,39/57,Distortions Caused by Taxes,US tax system is complexTaxes are collected at the federal, state, and city levelsConflicting incentivesTaxes that are not indexed distort the tax incentives for people to work, save, and investLower savings and investment means lower economic growt
38、h a real cost of inflation因為租稅造成的反向誘因，才是真正的成本,40/57,Inflation Increases the Cost of Cash通貨膨脹造成現金持有成本上升,If there is no inflation, cash holds its value over timeSome cash will be held for convenienceWhen inflation is high, cash loses value over time重點在於通貨膨脹時，現金放在銀行可以生利息，但是持有現金則無利息Manage cash balances
39、to limit lossesMore frequent, smaller withdrawals cost consumers and businesses time, travel a real cost of inflationBanks process more transactions, increasing costs another real cost of inflation更頻繁的取出現金與交易，造成成本的上升Costs of managing cash holding are called shoe leather costs, referring to the cost
40、of frequent trips to the bank,41/57,Unexpected Redistribution of Wealth非預期的物價膨脹造成財富重分配,Unexpected inflation redistributes wealthSuppose workers salaries are not indexed and inflation is higher than anticipatedSalaries lose purchasing power薪水階級受害Employers are less than anticipated in real termsEmploy
41、ers gain at the expense of workers雇主得利Similarly, unexpectedly high inflation benefits borrowers at the expense of lendersBorrowers repay with dollars worth less than anticipatedHurts creditors to the benefit of debtors借貸雙方的財富重分配Unanticipated inflation helps borrowers and hurts lenders有利於借款者但不利於放款者Un
42、expected inflation confuses incentives使得誘因機制混亂Interference with long-run planning擾亂長期計畫的規劃Difficult to forecast prices over long periods,42/57,Hyperinflation超級通貨膨脹,Hyperinflation, 500% 1000%A situation in which the inflation rate is “extremely” high極端快速的通貨膨脹Experienced by Several Latin American coun
43、triesIsraelTransition economies like RussiaConfederacy of U.S. 1861-1865同盟時期,92倍Magnifies the costs of inflation物價膨脹的成本更為擴大,43/57,辛巴威的超級通貨膨脹,44/57,貨幣供給量與通貨膨脹從民國三十七年發行的金圓券談起,當一國的財政支出遠大於收入，尤其是戰時龐大的軍費支出遠超過正常財政收入所能支應時，最直接的辦法就是以貨幣政策融通 (monetary accommodation)，也就是財政赤字的貨幣化 (monetizing budget deficit)。但是貨幣的
44、購買力來自於貨幣準備所提供的法償地位，過多的貨幣供給相對於過少的準備，會稀釋貨幣的購買力，使貨幣的法償地位受到質疑，幣值貶低，物價也就隨之上漲。這個現象可以由貨幣的供需均衡來探討。 從抗日戰爭到戰後期間的貨幣數量成長率來觀察，1937年6月的法幣發行量是14億元，1945年8月是5,567億元，八年間的貨幣發行量達到四百倍；十年後的1948年8月達到6,946萬億元，是1937年發行量的5百萬倍。更有甚者，1948年8月開始發行的金圓券發行量由初時限制的20億元額度，在不到一年期間的發行量就達到原額度的62萬5千倍，由此也就不難理解法幣以及金圓券時期的惡性通貨膨脹 (hyper-inflati
45、on)，都是由毫無限制的貨幣供給造成的。,45/57,陳飛龍顛沛悟生機2009-09-27中國時報【謝錦芳專訪】,問：當年離開上海時，是否通貨膨脹很嚴重？ 答：我記得學校老師領到薪水，當時是裝在布袋裡，馬上扛到雜貨店搬貨，因為只要晚一步，錢就貶值了。不過，雜貨店的老闆收下一布袋的錢，卻哭了出來，因為錢貶值得太厲害了。,46/57,Hyperinflation超級通貨膨脹,Hyperinflation is an extremely high rate of inflationIn 1923, German employers paid workers twice a dayMagnifies
46、the costs of inflationMinimize your cash holdingFischer et al. (2002), Journal of Economic LiteratureA study of market economies, 1960 1996 showed 45 episodes of high inflation (100+%) in 25 countriesReal GDP/person fell by an average of 1.6% per yearReal consumption/ person fell by an average of 1.
47、3% per yearReal investment per person fell by an average of 3.3% per year研究發現，超級通貨膨脹帶來真正成本,47/57,Nominal and Real Interest Rate名目與實質利率,Nominal interest rate (i.e., the market interest rate)The annual percentage increase in the nominal value of a financial asset金融資產價值年增率Real interest rate (i.e., real
48、 rate of return)The annual percentage increase in the purchasing power of a financial asset金融財貨的購買力年增加率Equals the nominal interest rate on that asset minus the inflation rate名目利率減去物價膨脹Financial investors and lenders do best when the real (not the nominal) interest rate is highIncreasing purchasing p
49、ower實質利率愈高,借錢出去的獲利愈大r = real interest rate 實質利率i = nominal, market, interest rate名目利率p = inflation rate通貨膨脹率,Inflation and Interest Rates,Nominal interest rates and inflation varyNominal interest rate range is 1.4% to 11.5%Inflation rate range is 2.7% to 13.5%Real interest rate is nominal interest rate minus inflationReal interest rate was highest in 1985, 3.9%Real interest rate was lowest in 1975, 3.3%,
