INDR 202
ENGINEERING ECONOMICS
CHAPTER 4
INFLATION
SPRING 2015
INSTRUCTOR: BORA ÇEKYAY
INFLATION
2
Measure of Inflation
INFLATION
3
Investment opportunity
INFLATION
DEFLATION
VALUE OF MONEY
EXAMPLE 1: PRICE OF BREAD
4
2006: 35 Kuruş
2010: 60 Kuruş
2006
100 TL
2006 2010
100 TL = 58.33 TL (2006)=(100/285.7)*166.7
100 TL could buy 285.7
loaves in 2006. 100 TL could buy 166.7 loaves in 2010.
EXAMPLE 2: PRICE OF GASOLINE
5
2000: $1.52/gallon
2013: $3.58/gallon
2000 $100
2000 2013
$100 = $42.46 (2000)
$100 could buy 65.79
gallons in 2000. $100 could buy 27.93 gallons in 2013.
EXAMPLE 3: PRICE OF MILK
6
Last year: $1.57/liter
Now: $1.25/liter
-1
$100
-1 0
$100 = $125.60 (-1)
$100 could buy 63.69
liters a year ago. $100 can now buy 80 liters.
PRICE INDICES
7 PRODUCER PRICE INDEX (PPI)
industrial price change (e.g., raw materials, finished products, operating costs)
CONSUMER PRICE INDEX (CPI)
price change for goods & services in major expenditure groups (e.g., food, housing, medical care) typically
CONSUMER PRICE INDEX (CPI)
8
MARKET BASKET: CONTENT & WEIGHTS
9
Food & Beverages (breakfast cereal, milk, chicken, wine) Housing (rent, furniture)
Apparel (men's shirts, women's dresses, jewelry)
Transportation (new vehicles, airline fares, gasoline) Medical Care (prescription drugs, hospital services)
Recreation (televisions, pets, sports equipment)
Education & Communication (college tuition, telephone) Other (smoking products, haircuts, funeral expenses)
CONSUMER PRICE INDEX (CPI)
11
MARKET BASKET
Base Period = 1967
2011
$100
$669.41
CONSUMER PRICE INDEX (CPI)
12
MARKET BASKET
Base Period =
2003
2008
2013
100 TL
154.66 TL
222.33 TL
INFLATION RATE
13 AVERAGE INFLATION RATE 𝒇
single rate that accounts for the effect of varying yearly inflation rates over a period of several years
GENERAL INFLATION RATE 𝒇"
average inflation rate based on CPI for all items in market basket
SPECIFIC INFLATION RATE
AVERAGE INFLATION RATE
14
YEAR 0
BASE PRICE
YEAR 1 PRICE
YEAR 2 PRICE
YEAR 1
4% INFLATION 8% INFLATIONYEAR 2
Actual inflated price at the end of year 2
$1 1 + 0.04 1 + 0.08 = $1.1232
Average inflation rate
AVERAGE INFLATION RATE
15
$1
$1.1232
0 1
2
4% 8%
$1
$1.1232
0 1
2
Example 11.1 Average Inflation Rate
Sample Calculation for Average Inflation rate
for Gasoline:
Given: P = 127.3, F =
175.3, N = 2009-‐2000 = 9.
Find: f
EXAMPLE 5: AVERAGE INFLATION RATE
17
Item 2011 Price 2000 Price Average
Inflation Rate Consumer Price Index (CPI)
(Base period: 82-84) $223.47 $171.20 2.45%
Postage $0.44 $0.33 2.65%
Homeowners Insurance $674 $500 2.75%
Private College Tuition, Fees $27,293 $15,518 5.27%
Gasoline (per gallon) $3.64 $1.56 8.01%
Haircut $21.00 $10.50 6.50%
Car (Toyota Camry) $22,590 $21,000 0.67%
GENERAL INFLATION RATE
18
𝑓̅
general inflation rate
CPI
7CPI at the end of period
𝑛
CPI
9CPI at the base period
CPI
7= CPI
91 + 𝑓̅
7𝑓̅ =
CPI
7CPI
9:/7
ANNUAL GENERAL INFLATION RATE
19
𝑓̅
7general inflation rate in period
𝑛
CPI
7CPI at the end of period
𝑛
CPI
7=:CPI at the end of period
𝑛 − 1
EXAMPLE 6: UTILITY COMPANY
20
A utility company’s cost of supplying a fixed amount of power to a housing development Year Cost 0 $504,000 1 $538,400 2 $577,000 3 $629,500
𝑓̅: = $538,400 − $504,000
$504,000 = 6.83%
𝑓̅. = $577,000 − $538,400
$538,400 = 7.17%
𝑓̅A = $629,500 − $577,000
$577,000 = 9.1%
𝑓̅ = $629,500 $504,000
:/A
ACTUAL VS. CONSTANT DOLLARS
21
Actual Dollars (
𝐴
7)
Ø estimates of future cash flows for year 𝑛 that take into
account any anticipated changes in amount caused by inflationary & deflationary effects
Ø amount of money paid or received regardless of how
much it is worth
Constant Dollars (
𝐴
C7)
Ø estimates of future cash flows for year 𝑛 in constant
purchasing power independent of the passage of time
Ø measure of worth with respect to base period
EXAMPLE 7: ACTUAL & CONSTANT DOLLARS
22
CONSTANT DOLLARS
$1,000
3
ACTUAL
DOLLARS $1,260
3
𝑛 = 3, 𝑓̅ = 8%
EXAMPLE 7: ACTUAL & CONSTANT DOLLARS
23
𝑛 = 3, 𝑓̅ = 8%
$1,260 1 + 0.08
=A= $1,000
CONSTANT DOLLARS
$1,000
3
ACTUAL
DOLLARS $1,260
EXAMPLE 8: MANUFACTURING
24
Year SalesUnit Net Cash Flows (constant $)
0 -250,000
1 1,000 100,000
2 1,100 110,000
3 1,200 120,000
4 1,300 130,000
5 1,200 120,000
Traffic-signal switching boxes Current price: $550
Manufacturing cost: $450
Start-up investment: $250,000
EXAMPLE 8: MANUFACTURING
25
Year Net Cash Flow in Constant $ Conversion Factor Net Cash Flow in Actual $
0 -$250,000 (1+0.05)0 -$250,000
1 $100,000 (1+0.05)1 $105,000
2 $110,000 (1+0.05)2 $121,275
3 $120,000 (1+0.05)3 $138,915
4 $130,000 (1+0.05)4 $158,016
EXAMPLE 8: MANUFACTURING
EXAMPLE 9: LAND LEASE
$20,000 (in actual dollars) to be paid at the beginning of each year for 5 years
General inflation rate 5% End of
Year in Actual $Cash Flow Conversion Factor Cash Flow in Constant $ Purchasing PowerPercent Loss in
0 $20,000 (1+0.05)0 $20,000 0
1 $20,000 (1+0.05)-1 $19,048 4.76
2 $20,000 (1+0.05)-2 $18,141 9.30
3 $20,000 (1+0.05)-3 $17,277 13.62
4 $20,000 (1+0.05)-4 $16,454 17.73
EQUIVALENCE CALCULATIONS
28 TYPES OF INTEREST RATES
§ Market Interest Rate
§ Inflation-Free Interest Rate
TYPES OF CASH FLOWS § Constant Dollars
§ Actual Dollars § Mixed
TYPES OF ANALYSIS METHODS § Constant-Dollar Analysis
§ Actual-Dollar Analysis (Deflation &
INTEREST RATES
29
Market interest rate
𝑖
(
inflation-adjusted
or
nominal
interest rate) combines the effects of the
earning power & any anticipated changes in
purchasing power.
Inflation-free interest rate
𝑖
C(
real
interest rate)
ANALYSIS METHODS
30
Constant-dollar analysis
estimates all future cash
flows in constant dollars.
When do we Prefer Constant Dollar Analysis?
In the absence of inflation, all economic analyses up
to this point is, in fact, the constant dollar analysis.
In constant dollar analysis, we should use the
inflation-‐free interest rate
𝒊′
.
Constant dollar analysis is common in the evaluation
of many long-‐term public projects, because
governments do not pay income taxes.
For private sector, income taxes are levied based on
EXAMPLE 10: MASTERS TOURNAMENT
32
Year Champion Winner’s Share
1934 Horton Smith $1,500
1962 Arnold Palmer $20,000 1975 Jack Nicklaus $40,000
1997 Tiger Woods $486,000
EXAMPLE 10: MASTERS TOURNAMENT
33
1962 90.42
2013
697.48
1967 100
CONSUMER PRICE INDEX
Average Inflation Rate
𝑓̅ = 697.48 90.42
:/J:
− 1 = 4.09%
EXAMPLE 10: MASTERS TOURNAMENT
34
If Arnold Palmer invested his prize in 1962 at inflation- free interest rate 4.477%,
$20,000 𝐹|𝑃, 4.477%, 51 = $186,675
Adam Scott’s prize in constant dollars w.r.t. 1962:
$1.44𝑀 𝑃|𝐹, 4.09%, 51 = $186,679
ACTUAL-DOLLAR ANALYSIS
35
Deflation Method
STEP 1: Convert all cash flows to constant dollars
(i.e., eliminate purchasing power discrepancy).
STEP 2: Incorporate the earning power. (inflation-
free interest rate)
Adjusted-Discount Method
36
EXAMPLE 11: DEFLATION METHOD
𝑛 Cash Flows in Actual Dollars
0 -$75,000 1 $32,000 2 $35,700 3 $32,800 4 $29,000 5 $58,000
General inflation rate 5%
Deflation Factor Constant DollarsCash Flows in
1 -$75,000
(1+0.05)-1 $30,476
(1+0.05)-2 $32,381
(1+0.05)-3 $28,334
(1+0.05)-4 $23,858
37
EXAMPLE 11: DEFLATION METHOD
𝑛 Constant DollarsCash Flows in
0 -$75.000 1 $30,476 2 $32,381 3 $28,334 4 $23,858 5 $45,445
Inflation-free interest rate 10%
$45,268
Discount Factor Present WorthEquivalent
1 -$75,000
(1+0.10)-1 $27,706
(1+0.10)-2 $26,761
(1+0.10)-3 $21,288
(1+0.10)-4 $16,295
38
EXAMPLE 11: DEFLATION METHOD
$32,000
-$75,000 $35,700 $32,800 $29,000 $58,000
Year 0 Year 1 Year 2 Year 3 Year 4 Year 5
Actual Dollars
$30,476
-$75,000 $32,381 $28,334 $23,858 $45,455
Constant Dollars
$27,706
-$75,000 $26,761 $21,288 $16,295 $28,218
Present Worth
39
ADJUSTED-DISCOUNT METHOD
𝑃
7=
𝐴
71 + 𝑓̅
71 + 𝑖
C 7=
𝐴
71 + 𝑖
7Market Interest Rate
40
EXAMPLE 11: ADJUSTED-DISCOUNT METHOD
𝑛 Cash Flows in Actual Dollars
0 -$75,000 1 $32,000 2 $35,700 3 $32,800 4 $29,000 5 $58,000
Market interest rate
𝑖 = 1 + 0. 05 1 + 0.10 − 1 = 15.5%
$45,268
Conversion
Factor Present WorthEquivalent
1 -$75,000
(1+0.155)-1 $27,706
(1+0.155)-2 $26,761
(1+0.155)-3 $21,288
(1+0.155)-4 $16,295
41
EXAMPLE 11: ADJUSTED-DISCOUNT METHOD
0
1 2 3 4 5
= $32,000 ( P |F , 15.5% , 1)
= $35,700 ( P|F , 15.5% , 2) = $32,800 ( P |F , 15.5% , 3)
= $29,000 ( P|F , 15.5% , 4)
42
EXAMPLE 11: ADJUSTED-DISCOUNT METHOD
$32,000
-$75,000 $35,700 $32,800 $29,000 $58,000
Year 0 Year 1 Year 2 Year 3 Year 4 Year 5
Actual Dollars
$27,706
-$75,000 $26,761 $21,288 $16,295 $28,218
Present Worth
43
MARKET INTEREST RATE
DISCRETE COMPOUNDING
𝑖 = 𝑖
C+ 𝑓̅ + 𝑖
C𝑓̅
CONTINUOUS COMPOUNDING
EXAMPLE 12: COLLEGE FUND
The parents of a 5-year old child make equal quarterly deposits into a college fund, starting at the end of 1st quarter until the child is 17.
The fund earns 8% interest compounded quarterly. The child will start college at the age of 18.
College expenses are estimated to be $30,000 per year (in today’s dollars).
College expenses will be paid at the beginning of every year for 4 years.
EXAMPLE 12: COLLEGE FUND
STEP 1: Convert all cash flows in constant $s to actual $s.
General inflation rate 6%
Age College Expenses (in constant $s)
18 $30,000
19 $30,000
20 $30,000
21 $30,000
Inflation Factor College Expenses (in actual $s)
(1+0.06)13 $63,988
(1+0.06)14 $67,827
(1+0.06)15 $71,897
EXAMPLE 12: COLLEGE FUND
EXAMPLE 12: COLLEGE FUND
STEP 2: Use market interest rate to find present value.
𝑉. = $63,988 𝑃|𝐹, 2%, 4 + $67, 827 𝑃|𝐹, 2%, 8
+$71,897 𝑃|𝐹, 2%, 12 + $76,211 𝑃|𝐹, 2%, 16 = $229,211
𝑉: = 𝐶 𝐹|𝐴, 2%, 48 = 79.3535𝐶 𝑉: = 𝑉.
SUMMARY
48
Consumer Price Index (CPI) measures the change, over time, in prices of goods & services in major expenditure groups.
Inflation describes a decline in purchasing power evidenced by increasing prices.
Deflation describes an increase in purchasing power evidenced by decreasing prices.
General Inflation Rate 𝑓̅ is an average inflation rate based on CPI. Annual general inflation rate 𝑓̅7 in year 𝑛 is:
𝑓̅7 = CPI7 − CPI7=:
SUMMARY
49
Price changes for specific, individual commodities are not always at general inflation rate. An average inflation rate
can be computed for a specific commodity based on an index (i.e., record of historical costs) for that commodity.
Cash flows may be given in actual dollars (reflecting inflation/deflation rates) or in constant dollars (reflecting purchasing power in base period).
Interest rates may be given as market interest rates
SUMMARY
50
Present worth of actual dollars can be calculated with:
Ø Deflation Method
STEP 1: Convert actual dollars to constant dollars by deflating with general inflation rate.
STEP 2: Calculate the present worth of constant dollars by discounting at inflation-free interest rate.
Ø Adjusted-Discount Method
STEP 1: Calculate the market interest rate.