1. Money Growth and Inflation30
Money Growth and Inflation
Economics
P R I N C I P L E S O F
N. Gregory Mankiw
For most students, the hardest concepts to grasp in this chapter are the most theoretical ones: the classical dichotomy and monetary neutrality. Most of the other material in the chapter is fairly straightforward for most students.
In the last section of the chapter – “The Costs of Inflation” – the Shoeleather cost is not difficult for students to understand, but it’s difficult for them to relate to, due to the ready availability of ATMs and Internet access to bank accounts. Most students have a harder time learning about the arbitrary redistributions of wealth that arise when inflation is different from expected.
This chapter is longer than average. To get through it more quickly, you might consider skipping or moving fairly quickly through some of the easier concepts, telling students to learn them from the textbook. Such concepts might include:
some of the costs of inflation (menu costs, confusion and inconvenience)
the inflation tax
hyperinflation
Premium PowerPoint Slides by Ron Cronovich

2. In this chapter, look for the answers to these questions:
How does the money supply affect inflation and nominal interest rates?화폐의 공급이 인플레와 명목이자율에 어떻게 영향을 미치는가?
Does the money supply affect real variables like real GDP or the real interest rate? 화폐 공급은 실질 GDP 또는 실질 이자율과 같은 실질 변수에 영향을 미치는가?
How is inflation like a tax? 어떻게 인플레이션은 조세와 유사한가?
What are the costs of inflation? How serious are they? 인플레의 비용은 무엇이며, 그것은 얼마나 심각한가? 1

3. Introduction
This chapter introduces the quantity theory of money to explain one of the Ten Principles of Economics from Chapter 1: 이 장에서는 이 책의 1장에서 소개한 다음의 원리를 설명하기 위해 화폐수량설을 도입한다.
Prices rise when the govt prints too much money. 정부가 돈을 많이 찍으면 가격이 오른다.
Most economists believe the quantity theory is a good explanation of the long run behavior of inflation. 대부분의 경제학자들은 화폐수량설이 인플레의 장기적 행태에 대한 좋은 설명이라고 믿는다.
MONEY GROWTH AND INFLATION 2

4. The Value of Money P = the price level (e.g., the CPI or GDP deflator)
P = the price level (e.g., the CPI or GDP deflator)
P is the price of a basket of goods, measured in money.
1/P is the value of $1, measured in goods.
Example: basket contains one candy bar.
If P = $2, value of $1 is 1/2 candy bar
If P = $3, value of $1 is 1/3 candy bar
Inflation drives up prices and drives down the value of money.
MONEY GROWTH AND INFLATION 3

5. The Quantity Theory of Money
Developed by 18th century philosopher David Hume and the classical economists 18세기의 철학자 흄과 고전파 경제학자들에 의해 발전
Advocated more recently by Nobel Prize Laureate Milton Friedman 최근 노벨상 수상자 밀턴 프리드먼에 의해 상찬됨
Asserts that the quantity of money determines the value of money 화폐량이 화폐의 가치를 결정한다고 주장
We study this theory using two approaches:
A supply-demand diagram
An equation
MONEY GROWTH AND INFLATION 4

6. Money Supply (MS)
In real world, determined by Federal Reserve, the banking system, consumers. 실제로는 중앙은행과 은행체계 그리고 소비자들이 결정
In this model, we assume the Fed precisely controls MS and sets it at some fixed amount. 이 모델에서는 중앙은행이 화폐공급을 세세히 통제하여 어떤 고정된 값으로 정할 수 있다고 가정
MONEY GROWTH AND INFLATION 5

7. Money Demand (MD)
Refers to how much wealth people want to hold in liquid form. 화폐수요란 사람들이 얼마나 많은 부를 유동적 형태로 보유하기를 원하는가를 나타낸다.
Depends on P: An increase in P reduces the value of money, so more money is required to buy g&s.물가가 상승하면 화폐가치가 떨어지기 때문에 g&s를 사는데 더 많은 화폐가 필요하다.
Thus, quantity of money demanded is negatively related to the value of money and positively related to P, other things equal.
(These “other things” include real income, interest rates, availability of ATMs.)
Some students may think that money demand is negatively related to P, reasoning that an increase in P reduces the demand for goods and services, so less money is required to buy goods & services. However, the relationship between P and money demand holds real income constant. Thus, “other things equal” means that an increase in P does NOT reduce real income, and therefore does not reduce the demand for goods and services.
Here’s a handy way to explain it:
Real income determines the quantity of g&s people demand.
P determines how many dollars will be needed to buy this quantity of g&s.
MONEY GROWTH AND INFLATION 6

8. The Money Supply-Demand Diagram
Value of Money, 1/P
Price Level, P
Quantity of Money 1
1.33 2 4
As the value of money rises, the price level falls.
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9. The Money Supply-Demand Diagram
Value of Money, 1/P
Price Level, P
Quantity of Money 1
1.33 2 4
MS1
$1000
The Fed sets MS at some fixed value, regardless of P.
MONEY GROWTH AND INFLATION 8

10. The Money Supply-Demand Diagram
A fall in value of money (or increase in P) increases the quantity of money demanded:
Value of Money, 1/P
Price Level, P
Quantity of Money 1
1.33 2 4
MD1
MONEY GROWTH AND INFLATION 9

11. The Money Supply-Demand Diagram
Value of Money, 1/P
Price Level, P
Quantity of Money 1
1.33 2 4
P adjusts to equate quantity of money demanded with money supply.
MS1
$1000
MD1
eq’m value of money
eq’m price level A
MONEY GROWTH AND INFLATION 10

12. The Effects of a Monetary Injection
Value of Money, 1/P
Price Level, P
Quantity of Money 1
1.33 2 4
MS1
$1000
MS2
$2000
MD1
Suppose the Fed increases the money supply.
Then the value of money falls, and P rises. A
eq’m value of money
eq’m price level B
MONEY GROWTH AND INFLATION 11

13. A Brief Look at the Adjustment Process
Result from graph: Increasing MS causes P to rise.
How does this work? Short version:
At the initial P, an increase in MS causes excess supply of money. 초기의 P에서 MS의 증가는 화폐의 초과공급을 야기한다.
People get rid of their excess money by spending it on g&s or by loaning it to others, who spend it. Result: increased demand for goods. 사람들은 남는 돈을 물건사는데 쓰거나 돈을 쓸 다른 사람에게 빌려준다. 결과적으로 재화에 대한 수요가 증가한다.
But supply of goods does not increase, so prices must rise. 재화공급 증가 않으므로 가격 상승
(Other things happen in the short run, which we will study in later chapters.)
MONEY GROWTH AND INFLATION 12

14. Real vs. Nominal Variables
Nominal variables are measured in monetary units. 명목변수는 화폐단위로 측정된다.
Examples: nominal GDP, nominal interest rate (rate of return measured in $) nominal wage ($ per hour worked)
Real variables are measured in physical units.실질변수는 물질 단위로 측정된다.
Examples: real GDP, real interest rate (measured in output) real wage (measured in output)
Students seem to readily understand that the real wage is the purchasing power of the wage, or that the real wage is corrected for inflation. From either of these interpretations of the real wage, it is just a small step to understand that the real wage is measured in units of output.
What does “the purchasing power of the wage” mean? If students think about it, they will grasp that it means the quantity of output workers can buy with their wage. Hence, the real wage is measured in units of output.
What does “corrected for inflation” mean? A simple example helps. Suppose the nominal wage rises 20% and the price level also rises 20%. Students will immediately understand that the wage – corrected for inflation – is unchanged. Which is to say, it can buy the same quantity of output as before.
The next slide discusses relative prices, demonstrating that they, too, are measured in physical units, which makes them real variables. The following slide returns to the real wage, showing that it is a relative price, and demonstrating that it is measured in units of output.
How is it that the real interest rate is measured in output? Suppose we measure the value of a deposit in terms of how much output the deposit can buy (i.e., the purchasing power of the deposit). Then, think of the real interest rate as the rate at which the purchasing power of the deposit grows. Thinking in these terms, students should begin to grasp that the real interest rate is the amount of output earned on the deposit (as a % of the deposit).
MONEY GROWTH AND INFLATION 13

15. Real vs. Nominal Variables
Prices are normally measured in terms of money.
Price of a compact disc: $15/cd
Price of a pepperoni pizza: $10/pizza
A relative price is the price of one good relative to (divided by) another:
Relative price of CDs in terms of pizza:
price of cd
price of pizza
$15/cd
$10/pizza =
= 1.5 pizzas per cd
Relative prices are measured in physical units, so they are real variables.
MONEY GROWTH AND INFLATION 14

16. Real vs. Nominal Wage An important relative price is the real wage:
An important relative price is the real wage:
W = nominal wage = price of labor, e.g., $15/hour
P = price level = price of g&s, e.g., $5/unit of output
Real wage is the price of labor relative to the price of output: W P
$15/hour
$5/unit of output =
= 3 units output per hour
MONEY GROWTH AND INFLATION 15

17. The Classical Dichotomy고전적 이분법
Classical dichotomy: the theoretical separation of nominal and real variables 명목변수와 실질변수의 이론적 분리
Hume and the classical economists suggested that monetary developments affect nominal variables but not real variables. 흄과 고전학파는 화폐의 증가는 명복변수에 영향을 미치지만 실질변수에는 영향을 미치지 않는다고 주장
If central bank doubles the money supply, Hume & classical thinkers contend 중앙은행이 화폐공급을 두배로 늘이면
all nominal variables – including prices – will double. 가격을 포함한 모든 명목변수는 두배가 되고
all real variables – including relative prices – will remain unchanged. 모든 실질변수는 변화하지 않는다고 주장
MONEY GROWTH AND INFLATION 16

18. The Neutrality of Money화폐의 중립성
Monetary neutrality: the proposition that changes in the money supply do not affect real variables
Doubling money supply causes all nominal prices to double; what happens to relative prices?
Initially, relative price of cd in terms of pizza is
price of cd
price of pizza
= 1.5 pizzas per cd
$15/cd
$10/pizza =
This result is important because relative prices, not nominal prices, determine the economy’s allocation of resources.
The relative price is unchanged.
After nominal prices double,
price of cd
price of pizza
= 1.5 pizzas per cd
$30/cd
$20/pizza =
MONEY GROWTH AND INFLATION 17

19. The Neutrality of Money
Monetary neutrality: the proposition that changes in the money supply do not affect real variables
Similarly, the real wage W/P remains unchanged, so
quantity of labor supplied does not change
quantity of labor demanded does not change
total employment of labor does not change
The same applies to employment of capital and other resources.
Since employment of all resources is unchanged, total output is also unchanged by the money supply.
The material on this slide does not appear explicitly in this chapter, but it helps explain how money can be neutral.
MONEY GROWTH AND INFLATION 18

20. The Neutrality of Money
Most economists believe the classical dichotomy and neutrality of money describe the economy in the long run. 대부분의 경제학자는 고전적 이분법과 화폐의 중립성은 장기에서의 경제를 설명한다고 믿는다.
In later chapters, we will see that monetary changes can have important short-run effects on real variables. 다음 장들에서 우리는 화폐적 변화가 실질변수에 중대한 단기적 영향을 미칠 수 있음을 볼 것이다.
MONEY GROWTH AND INFLATION 19

21. The Velocity of Money Velocity formula: P x Y V = M
Velocity of money: the rate at which money changes hands화폐의 유통속도란 화폐가 한사람에게서 다른 사람에게로 이동하는 빈도
Notation: P x Y = nominal GDP = (price level) x (real GDP)
M = money supply
V = velocity
Velocity formula:
The textbook’s definition of velocity appears on this slide. You may prefer a more precise definition: The number of transactions in which the average dollar is used.
The following slide provides a simple example to clarify the meaning of velocity.
V =
P x Y M
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22. The Velocity of Money P x Y Velocity formula: V = M
V =
P x Y M
Velocity formula:
Example with one good: pizza. In 2008,
Y = real GDP = 3000 pizzas
P = price level = price of pizza = $10
P x Y = nominal GDP = value of pizzas = $30,000
M = money supply = $10,000
V = velocity = $30,000/$10,000 = 3
The average dollar was used in 3 transactions.
If $10,000 worth of money purchases $30,000 worth of pizza, it must be true that the average dollar is used three times.
MONEY GROWTH AND INFLATION 21

23. A C T I V E L E A R N I N G 1 Exercise
One good: corn.
The economy has enough labor, capital, and land to produce Y = 800 bushels of corn.
V is constant.
In 2008, MS = $2000, P = $5/bushel.
Compute nominal GDP and velocity in 2008. 22

24. A C T I V E L E A R N I N G 1 Answers
Given: Y = 800, V is constant, MS = $2000 and P = $5 in 2005.
Compute nominal GDP and velocity in 2008.
Nominal GDP = P x Y = $5 x 800 = $4000
V =
P x Y M =
$4000
$2000
= 2 23

25. U.S. Nominal GDP, M2, and Velocity (1960=100) 1960-2007
U.S. Nominal GDP, M2, and Velocity (1960=100)
Nominal GDP M2
Velocity is fairly stable over time.
Note: Each variable has been scaled to equal 100 to make variables comparable.
This graph replicates Figure 3 in the textbook. Its purpose is to demonstrate that velocity is fairly stable over time. This observation justifies the assumption of constant velocity in the quantity theory of money.
Original sources:
M2 is from Board of Governors, Federal Reserve Board
GDP is from U.S. Department of Commerce, Bureau of Economic Analysis.
I obtained all data from FRED database, Federal Reserve Bank of St. Louis, at:
Velocity 24

26. The Quantity Equation P x Y Velocity formula: V = M
V =
P x Y M
Velocity formula:
Multiply both sides of formula by M:
M x V = P x Y
Called the quantity equation 화폐수량방정식
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27. The Quantity Theory in 5 Steps
Start with quantity equation: M x V = P x Y
1. V is stable.
2. So, a change in M causes nominal GDP (P x Y) to change by the same percentage.
3. A change in M does not affect Y: money is neutral, Y is determined by technology & resources
4. So, P changes by same percentage as P x Y and M.
5. Rapid money supply growth causes rapid inflation.
MONEY GROWTH AND INFLATION 26

28. A C T I V E L E A R N I N G 2 Exercise
One good: corn. The economy has enough labor, capital, and land to produce Y = 800 bushels of corn. V is constant. In 2008, MS = $2000, P = $5/bushel.
For 2009, the Fed increases MS by 5%, to $2100.
a. Compute the 2009 values of nominal GDP and P. Compute the inflation rate for
b. Suppose tech. progress causes Y to increase to 824 in Compute inflation rate.
This exercise makes the quantity theory more concrete for students.
If you’re pressed for time, you can delete part b or ask students to do it on their own. 27

29. A C T I V E L E A R N I N G 2 Answers
A C T I V E L E A R N I N G Answers
Given: Y = 800, V is constant, MS = $2000 and P = $5 in 2008.
For 2009, the Fed increases MS by 5%, to $2100.
a. Compute the 2009 values of nominal GDP and P. Compute the inflation rate for
Nominal GDP = P x Y
= M x V (Quantity Eq’n)
= $2100 x 2 = $4200
P x Y Y
$4200
800
P = =
= $5.25
$5.25 – 5.00
5.00
Inflation rate =
= 5% (same as MS!) 28

30. A C T I V E L E A R N I N G 2 Answers
Given: Y = 800, V is constant, MS = $2000 and P = $5 in 2005.
For 2009, the Fed increases MS by 5%, to $2100.
b. Suppose tech. progress causes Y to increase 3% in 2009, to Compute inflation rate.
First, use Quantity Eq’n to compute P:
M x V Y
$4200
824
P = =
= $5.10
$5.10 – 5.00
5.00
Inflation rate =
= 2% 29

31. Economic growth increases # of transactions.
A C T I V E L E A R N I N G Summary and Lessons about the Quantity Theory of Money
If real GDP is constant, then 실질 GDP가 일정하면 inflation rate = money growth rate. 인플레율=통화증가율
If real GDP is growing, then 실질 GDP가 증가하면 inflation rate < money growth rate. 인플레율<통화증가율
The bottom line: 결론
Economic growth increases # of transactions.
Some money growth is needed for these extra transactions.
Excessive money growth causes inflation. 30

32. Hyperinflation 초인플레이션
Hyperinflation is generally defined as inflation exceeding 50% per month. 한 달에 50%이상의 인플레이션
Recall one of the Ten Principles from Chapter 1: Prices rise when the government prints too much money.
Excessive growth in the money supply always causes hyperinflation. 화폐공급의 지나친 증가는 항상 초인플레를 초래한다.
MONEY GROWTH AND INFLATION 31

33. The Inflation Tax인플레이션 조세
When tax revenue is inadequate and ability to borrow is limited, govt may print money to pay for its spending. 조세수입이 불충분하고 차입능력이 제한되어 있을 때 정부는 지출을 위해 화폐를 발행한다.
Almost all hyperinflations start this way.
The revenue from printing money is the inflation tax: printing money causes inflation, which is like a tax on everyone who holds money. 화폐발행은 인플레를 초래하는데 이는 모든 화폐보유자에게 부과되는 조세와 같다.
In the U.S., the inflation tax today accounts for less than 3% of total revenue. 미국에서 인플레 조세는 총 수입의 3%에 약간 못미친다.
MONEY GROWTH AND INFLATION 32

34. The Fisher Effect피셔효과
Rearrange the definition of the real interest rate:
Real interest rate
Nominal interest rate
Inflation rate + =
The real interest rate is determined by saving & investment in the loanable funds market.
Money supply growth determines inflation rate.
So, this equation shows how the nominal interest rate is determined.
MONEY GROWTH AND INFLATION 33

35. The Fisher Effect Real interest rate Nominal interest rate
Real interest rate
Nominal interest rate
Inflation rate + =
In the long run, money is neutral, so a change in the money growth rate affects the inflation rate but not the real interest rate. 장기에 화폐는 중립적이므로 통화증가율은 실질이자율에는 영향을 미치지 못하고 인플레율만 영향을 미친다.
So, the nominal interest rate adjusts one-for-one with changes in the inflation rate. 따라서 명목 이자율은 인플레율의 변화와 같은 폭으로 변화한다.
This relationship is called the Fisher effect after Irving Fisher, who studied it. 이러한 관계를 피셔효과라고 함
MONEY GROWTH AND INFLATION 34

36. U.S. Nominal Interest & Inflation Rates, 1960-2007
The close relation between these variables is evidence for the Fisher effect.
The nominal interest rate is the 3-month Treasury Bill rate. The inflation rate is calculated as the percent change in the CPI from 12 months earlier.
Mostly, these two variables move very closely together: increases in inflation correspond to similar increases in the nominal interest rate.
When the two variables are not moving precisely together, the real interest rate is changing. This would occur if, for example, there were changes in the supply and/or demand for loanable funds. Starting in the early 1980s, the emergence of huge budget deficits caused the supply of loanable funds to fall, which increased the real interest rate. On this graph, the gap between the nominal interest rate and inflation rate clearly grows in the early 1980s.
Original sources:
CPI, not seasonally adjusted: Bureau of Labor Statistics, U.S. Department of Labor
Treasury Bill rate: Board of Governors of the Federal Reserve System
Where I obtained this data:
FRED database, Federal Reserve Bank of St. Louis 35 35

37. The Fisher Effect & the Inflation Tax
Real interest rate
Nominal interest rate
Inflation rate + =
The inflation tax applies to people’s holdings of money, not their holdings of wealth. 인플레이션 조세는 사람들의 화폐보유량에 부과되는 것이지 부의 보유량에 부과되는 것은 아니다.
The Fisher effect: an increase in inflation causes an equal increase in the nominal interest rate, so the real interest rate (on wealth) is unchanged. 즉 인플레의 증가에도 불구하고 부에서 유래하는 실질이자율은 변함이 없다.
MONEY GROWTH AND INFLATION 36

38. The Costs of Inflation
The inflation fallacy: most people think inflation erodes real incomes. 대부분의 사람들은 인플레가 실질소득의 감소를 가져온다고 생각
But inflation is a general increase in prices of the things people buy and the things they sell (e.g., their labor).그러나 인플레는 사람들이 사고 파는 모든 것들의 가격을 모두 올린다(즉 노동의 가격도 오른다)
In the long run, real incomes are determined by real variables, not the inflation rate. 장기에 실질소득은 실질변수에 의해 결정되지 인플레율에 의해 결정되지 않는다.
MONEY GROWTH AND INFLATION 37

39. U.S. Average Hourly Earnings & the CPI
Inflation causes the CPI and nominal wages to rise together over the long run.
Nominal wage (right scale)
This graph is not in the textbook, but it helps expose the inflation fallacy.
Note: If you change the scale of the CPI axis, you can make it look like the CPI is rising faster or slower than the average worker’s nominal wage. However, you can normalize both series to equal 100 in 1965 and plot them on the same vertical axis, and the result would be remarkably similar to what you see here: the average wage divided by the CPI is virtually the same today as 40 years ago (despite a few ups and downs in the interim, which of course should not be surprising, as the determinants of the real wage - labor supply and the marginal product of labor – are not likely to be constant over such a long time period).
I decided to go with this graph instead of a graph of the two variables equal to 100 in 1965 because the units of this graph are more natural, and because it gives students practice interpreting graphs with variables measured on different scales.
The nominal wage is average hourly earnings, total for private sector, seasonally adjusted, from the Bureau of Labor Statistics, U.S. Department of Labor. The CPI in this graph is seasonally adjusted, also from the BLS.
CPI (left scale) 38 38

40. The Costs of Inflation
Shoeleather costs: the resources wasted when inflation encourages people to reduce their money holdings 인플레이션에 직면한 경제주체들이 현금보유를 줄이는 과정에서 낭비되는 자원
Includes the time and transactions costs of more frequent bank withdrawals
Menu costs: the costs of changing prices
Printing new menus, mailing new catalogs, etc.가격을 변동시키는데 드는 비용
MONEY GROWTH AND INFLATION 39

41. The Costs of Inflation
Misallocation of resources from relative-price variability(상대가격 변화로 인한 자원배분의 왜곡): Firms don’t all raise prices at the same time, so relative prices can vary…
which distorts the allocation of resources.
Confusion & inconvenience(혼란과 불편): Inflation changes the yardstick we use to measure transactions.
Complicates long-range planning and the comparison of dollar amounts over time.
MONEY GROWTH AND INFLATION 40

42. The Costs of Inflation Tax distortions(조세 왜곡):
Tax distortions(조세 왜곡):
Inflation makes nominal income grow faster than real income. 인플레는 명목임금이 실질임금보다 빠르게 상승하도록 한다.
Taxes are based on nominal income, and some are not adjusted for inflation. 조세는 명목임금에 기초하고 있고 일부는 인플레를 감안하여 조정되지 않는다.
So, inflation causes people to pay more taxes even when their real incomes don’t increase. 따라서 인플레는 실질임금이 오르지 않는 경우에도 보다 많은 세금을 내도록 만든다.
MONEY GROWTH AND INFLATION 41

43. A C T I V E L E A R N I N G 3 Tax distortions
You deposit $1000 in the bank for one year.
CASE 1: inflation = 0%, nom. interest rate = 10%
CASE 2: inflation = 10%, nom. interest rate = 20%
a. In which case does the real value of your deposit grow the most?
Assume the tax rate is 25%.
b. In which case do you pay the most taxes?
c. Compute the after-tax nominal interest rate, then subtract off inflation to get the after-tax real interest rate for both cases.
Most principles-level students have difficulty the first time they are asked to calculate the after-tax real interest rate because the calculation involves several intermediate steps. The intermediate steps are, at first, not obvious to most students. This exercise walks students through these steps.
The exercise leads students to see for themselves that inflation reduces the after-tax real interest rate.
Suggestion: Display this slide, and give students 3-4 minutes to work the problem on their own. 42

44. A C T I V E L E A R N I N G 3 Answers
Deposit = $1000.
CASE 1: inflation = 0%, nom. interest rate = 10%
CASE 2: inflation = 10%, nom. interest rate = 20%
a. In which case does the real value of your deposit grow the most?
In both cases, the real interest rate is 10%, so the real value of the deposit grows 10% (before taxes).
Suggestion: If you can spare the class time, ask students for the answers before you display them. 43

45. A C T I V E L E A R N I N G 3 Answers
Deposit = $ Tax rate = 25%.
CASE 1: inflation = 0%, nom. interest rate = 10%
CASE 2: inflation = 10%, nom. interest rate = 20%
b. In which case do you pay the most taxes?
CASE 1: interest income = $100, so you pay $25 in taxes.
CASE 2: interest income = $200, so you pay $50 in taxes. 44

46. A C T I V E L E A R N I N G 3 Answers
Deposit = $ Tax rate = 25%.
CASE 1: inflation = 0%, nom. interest rate = 10%
CASE 2: inflation = 10%, nom. interest rate = 20%
c. Compute the after-tax nominal interest rate, then subtract off inflation to get the after-tax real interest rate for both cases.
CASE 1: nominal = x 10% = 7.5%
real = 7.5% – 0% = 7.5%
CASE 2: nominal = x 20% = 15%
real = 15% – 10% = 5% 45

47. A C T I V E L E A R N I N G 3 Summary and lessons
Deposit = $ Tax rate = 25%.
CASE 1: inflation = 0%, nom. interest rate = 10%
CASE 2: inflation = 10%, nom. interest rate = 20%
Inflation…
raises nominal interest rates (Fisher effect) but not real interest rates
increases savers’ tax burdens
lowers the after-tax real interest rate
By lowering the after-tax interest rate, inflation reduces the incentive to save. Recall that saving is critically important for future productivity and living standards. 46

48. A Special Cost of Unexpected Inflation
Arbitrary redistributions of wealth Higher-than-expected inflation transfers purchasing power from creditors to debtors: Debtors get to repay their debt with dollars that aren’t worth as much.
Lower-than-expected inflation transfers purchasing power from debtors to creditors.
High inflation is more variable and less predictable than low inflation.
So, these arbitrary redistributions are frequent when inflation is high.
For many students, this is one of the harder concepts of the chapter. You might consider asking students to work through Problem 10 in the “Problems and Applications” at the end of this chapter for practice with this concept.
MONEY GROWTH AND INFLATION 47

49. The Costs of Inflation
All these costs are quite high for economies experiencing hyperinflation.
For economies with low inflation (< 10% per year), these costs are probably much smaller, though their exact size is open to debate.
MONEY GROWTH AND INFLATION 48

50. CONCLUSION
This chapter explains one of the Ten Principles of economics: Prices rise when the govt prints too much money.
We saw that money is neutral in the long run, affecting only nominal variables.
In later chapters, we will see that money has important effects in the short run on real variables like output and employment.
MONEY GROWTH AND INFLATION 49

51. CHAPTER SUMMARY
To explain inflation in the long run, economists use the quantity theory of money. According to this theory, the price level depends on the quantity of money, and the inflation rate depends on the money growth rate.
The classical dichotomy is the division of variables into real & nominal. The neutrality of money is the idea that changes in the money supply affect nominal variables but not real ones. Most economists believe these ideas describe the economy in the long run. 50

52. CHAPTER SUMMARY
The inflation tax is the loss in the real value of people’s money holdings when the government causes inflation by printing money.
The Fisher effect is the one-for-one relation between changes in the inflation rate and changes in the nominal interest rate.
The costs of inflation include menu costs, shoeleather costs, confusion and inconvenience, distortions in relative prices and the allocation of resources, tax distortions, and arbitrary redistributions of wealth. 51