ELASTICITY IMBA Managerial Economics Jack Wu
Jan 12, 2016
ELASTICITYIMBA Managerial Economics
Jack Wu
AMERICAN AIRLINES
“Extensive research and many years of experience have taught us that business travel demand is quite inelastic… On the other hand, pleasure travel has substantial elasticity.”
Robert L. Crandall, CEO, 1989
OWN-PRICE ELASTICITY: E=Q%/P%
Definition: percentage change in quantity demanded resulting from 1% increase in price of the item.Alternatively,
n_price%_change_i
_demandedn_quantity%_change_i
CALCULATING ELASTICITY
1.1
1.0
1.44 1.5
CALCULATING ELASTICITY
Arc Approach:
Elasticity={[Q2-Q1]/avgQ}/{[P2-P1]/avgP
% change in qty = (1.44-1.5)/1.47 = -4.1% % change in price = (1.10-1)/1.05 = 9.5% Elasticity=-4.1%/9.5% =-0.432
CALCULATING ELASTICITY
Point approach: Elasticity={[Q2-Q1]/Q1}/{[P2-P1]/P1}
% change in qty = (1.44-1.5)/1.5= -4%% change in price = (1.10-1)/1= 10%Elasticity=-4%/10%=-0.4
OWN-PRICE ELASTICITY
|E|=0, perfectly inelastic 0<|E|<1, inelastic |E|=1, unit elastic |E|>1, elastic |E|=infinity, perfectly elastic
SLOPE/ELASTICITY
• steeper demand curve <--> demand less elastic
• slope is not the same as elasticity
0 Quantity
Price
DEMAND CURVES
perfectly elastic demand
perfectly inelastic demand
LINEAR DEMAND CURVE
Vertical intercept: perfectly elastic Upper segment: elastic Middle: Unit elastic Lower segment: inelastic Horizontal intercept: perfectly inelastic
Product Market ElasticityAutomobilesChevette U.S. -3.2Civic U.S. -4Consumer productsmusic CDs Aus -1.83cigarettes U.S. -0.3liquor U.S. -0.2football games U.S. -0.275Utilitieselectricity (residential) Quebec -0.7telephone service Spain -0.1water (residential) U.S. -0.25water (industrial) U.S. -0.85
OWN-PRICE ELASTICITIES
OWN-PRICE ELASTICITY: DETERMINANTS
availability of direct or indirect substitutes
cost / benefit of economizing (searching for better price)
buyer’s prior commitments
separation of buyer and payee
AADVANTAGE1981: American Airlines pioneered frequent flyer program buyer commitment business executives fly at the expense of others
WHEN TO RAISE PRICE
CEO: “Profits are low. We must raise prices.”
Sales Manager: “But my sales would fall!”
Real issue: How sensitive are buyers to price changes?
PRICE INCREASE: EXPENDITURE
if demand elastic, expenditure will fall
if demand inelastic, expenditure will rise
INCOME ELASTICITY, I=Q%/Y%
Definition: percentage change in quantity demanded resulting from 1% increase in income.Alternatively,
n_income%_change_i
_demandedn_quantity%_change_i
INCOME ELASTICITY
I >0, Normal good I <0, Inferior good Among normal goods: 0<I<1, necessity I>1, luxury
Item Market ElasticityConsumer productscigarettes U.S. 0.1liquor U.S. 0.2food U.S. 0.8clothing U.S. 1newspapers U.S. 0.9Utilitieselectricity (residential) Quebec 0.1telephone service Spain 0.5
INCOME ELASTICITY
CROSS-PRICE ELASTICITY: C=Q%/PO%
Definition: percentage change in quantity demanded for one item resulting from 1% increase in the price of another item.
(%change in quantity demanded for one item) / (% change in price of another item)
CROSS-PRICE ELASTICITY
C>0, Substitutes C<0, complements C=0, independent
Item Market ElasticityConsumer productsclothing/food U.S. 0.1gasoline (competing stn) Boston, MA 1.2Utilitieselectricity/gas (residential) Quebec 0.1electricity/oil (residential) Quebec 0bus/subway London 0.25
CROSS-PRICE ELASTICITIES
ADVERTISING ELASTICITY: A=Q%/A%
Definition: percentage change in quantity demanded resulting from 1% increase in advertising expenditure.
Product Market Elasticitybeer U.S. 0wine U.S. 0.08cigarettes U.S. 0.04clothing U.S. 0.01hypert. drugs U.S. 0.23 - 0.25recreation U.S. 0.08
ADVERTISING ELASTICITIES
ADVERTISING
direct effect: raises demand indirect effect: makes demand less sensitive
to price
Own price elasticity for antihypertensive drugsWithout advertising: -2.05With advertising: -1.6
FORECASTING DEMAND
Q%=E*P%+I*Y%+C*Po%+a*A%
FORECASTING DEMAND
Effect on cigarette demand of 10% higher income 5% less advertising
change elas. effect
income 10% 0.1 1%
advert. -5% 0.04 -0.2%
net +0.8%
ADJUSTMENT TIME
short run: time horizon within which a buyer cannot adjust at least one item of consumption/usage
long run: time horizon long enough to adjust all items of consumption/usage
ADJUSTMENT TIME
For non-durable items, the longer the time that buyers have to adjust, the bigger will be the response to a price change.
For durable items, a countervailing effect (that is, the replacement frequency effect) leads demand to be relatively more elastic in the short run.
0
4.5
5
1.5 1.6 1.75
long-run demand
short-run demand
Quantity (Million units a month)
Pri
ce (
$ p
er
unit
)
NON-DURABLE: SHORT/LONG-RUN DEMAND
Item Factor Market Short-run Long-runNondurablescigarettes price U.S. -0.3 -3.3liquor price U.S./Canada -0.2 -1.8gaseline price U.S. -0.1 -0.5
income U.S. 0 0.3bus price London -0.8 -1.3subway price London -0.4 -0.7railway price Philadelphia -0.5 -1.8Durablesautomobiles price U.S. -0.2 -0.5
income U.S. 3 1.4
SHORT/LONG-RUN ELASTICITIES
STATISTICAL ESTIMATION: DATA
time series – record of changes over time in one market
cross section -- record of data at one time over several markets
Panel data: cross section over time
MULTIPLE REGRESSION
Statistical technique to estimate the separate effect of each independent variable on the dependent variable dependent variable = variable whose changes are to be explained independent variable = factor affecting the dependent variable
DISCUSSION QUESTION 1
Among commercial users such as apartment buildings, hotels, and offices, the demand for water is estimated to have an own-price elasticity was -0.36, the elasticity with respect to the number of commercial establishments was 0.99, and the elasticity with respect to the average summer temperature was 0.02 (Williams and Suh, 1986).
DISCUSSION QUESTION 1:CONTINUED
Intuitively, would an increase in the number of commercial establishments increase or reduce the demand for water? Is the estimated elasticity consistent with your explanation?
Intuitively, would a rise in the average summer temperature increase or reduce the demand for water? Is the estimated elasticity consistent with your explanation?
By considering the own-price elasticity of demand, explain how the water company could increase its profit.
DISCUSSION QUESTION 2
Drugs that are not covered by patent can be freely manufactured by anyone. By contrast, the production and sale of patented drugs is tightly controlled. The advertising elasticity of the demand for antihypertensive drugs was around 0.26 for all drugs, and 0.24 for those covered by patents. For all antihypertensive drugs, the own price elasticity was about -2.0 without advertising, and about -1.6 in the long run with advertising.
DISCUSSION QUESTION 2:CONTINUED
Consider a 5% increase in advertising expenditure. By how much would the demand for a patented drug rise? What about the demand for a drug not covered by patent?
Why is the demand for patented drugs less responsive to advertising than the demand for drugs not covered by patent?
Suppose that a drug manufacturer were to increase advertising. Explain why it should also raise the price of its drugs.
DISCUSSION QUESTION 3
An Australian telecommunications carrier wants to estimate the own-price elasticity of the demand for international calls to the United States. It has collected annual records of international calls and prices. In each of the following groups, choose the one factor that you would also consider in the regression equation. Explain your reasoning.
DISCUSSION QUESTION 3: CONTINUED
Consumer characteristics: (i) average per capita income, (ii) average age.
Complements: (i) number of telephone lines, (ii) number of mobile telephone subscribers.
Prices of related items: (i) price of electricity, (ii) postage rate from Australia to the United States.