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ELASTICITIES (CONTINUED………….):Short Run and Long Run, Incidence of Taxation

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Introduction to Economics ­ECO401
VU
Lesson 3.3
ELASTICITIES (CONTINUED.............)
If the sign of income elasticity of demand is positive, the good is normal and if sign is negative,
the good is inferior.
Determinants of Income Elasticity of Demand:
The determinants of income elasticity of demand are:
·  Degree of necessity of good.
·
The rate at which the desire for good is satisfied as consumption increases
·
The level of income of consumer.
Short Run and Long Run:
Short run is a period in which not all factors can adjust fully and therefore adjustment to
shocks can only be partial.
Long run is a period over which all factors can be changed and full adjustment to shocks can
take place.
Incidence of Taxation:
A tax results in a vertical shift of the supply curve as it increases the cost of producing the
taxed product.
The incidence of taxation relates to how much of the tax's burden is being borne by
consumers and producers. The more inelastic the demand, the more of the tax's burden will
fall on consumers. The more inelastic the supply, the more of the tax's burden will fall on
producers.
Terms of trade means the `real' terms at which a nation sells its exports and buys its import.
OPEC: Organization of Petroleum Exporting Countries.
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Introduction to Economics ­ECO401
VU
END OF UNIT 3 ­ EXERCISES
Why will the price elasticity of demand for a particular brand of a product (e.g. Shell) be
greater than that for the product in general (e.g. petrol)? Is this difference the result of a
difference in the size of the income effect or the substitution effect?
The price elasticity of demand for a particular brand is more elastic than that for a product in
general because people can switch to an alternative brand if the price of one brand goes up. No
such switching will take place if the price of the product in general (i.e. all brands) goes up. Thus
the difference in elasticity is the result of a difference in the size of the substitution effect.
Will a general item of expenditure like food (or clothing) have a price-elastic or inelastic
demand? Discuss in the context of income and substitution effects.
The income effect will be relatively large (making demand relatively elastic). The substitution
effect will be relatively small (making demand relatively inelastic). The actual elasticity will
depend on the relative size of these two effects.
Demand for oil might be relatively elastic over the longer term, and yet it could still be
observed that over time people consume more oil (or only very slightly less) despite
rising oil prices. How can this apparent contradiction be explained?
Because, there has been a rightward shift in the demand curve for oil. This is likely to be the
result of rising incomes. Car ownership and use increase as incomes increase. Also tastes may
have changed so that people want to drive more. There may also have been a decline in
substitute modes of transport such as rail transport and buses. Finally, people may travel longer
distances to work as a result of a general move to the suburbs.
Assume that demand for a product is inelastic.  Will consumer expenditure go on
increasing as price rises? Would there be any limit?
So long as demand remains inelastic with respect to price, then consumer expenditure will go on
rising as price rises. However, if the price is raised high enough, demand always will become
elastic.
Can you think of any examples of goods which have a totally inelastic demand (a) at all
prices; (b) over a particular price range?
a) No goods fit into this category, otherwise price could rise to infinity with no fall in demand
­ but people do not have infinite incomes!
b) Over very small price ranges, the demand for goods with no close substitutes, oil, water
(where it is scarce) may be totally inelastic.
What will the demand curve corresponding to the following table look like?
If the curve had an elasticity of ­1 throughout its length, what would be the quantity
demanded (a) at a price of Ł1; (b) at a price of 10p; (c) if the good were free?
Q
Total
P (Ł)
Expenditure
(Ł)
2.5
400
1000
5
200
1000
10
100
1000
20
50
1000
40
25
1000
The curve will be a `rectangular hyperbola': it will be a smooth curve, concave to the origin
which never crosses either axis (Qd = 1000/P).
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Introduction to Economics ­ECO401
VU
a. 1000 units.
b. 10 000 units.
c. There would be infinite demand!
Referring to the following table, use the mid-point (arc) formula to calculate the price
elasticity of demand between (a) P = 6 and P = 4; (b) P = 4 and P = 2. What do you
conclude about the elasticity of a straight-line demand curve as you move down it?
Price Quantity Demanded
6
20
5
25
4
30
3
35
2
40
Using the formula: (ΔQ/mid Q) ÷ (ΔP/mid P) gives the following answers:
(a) 10/25 ÷ ­2/5
= 10/25 × 5/­2
= 50/­50
= ­1 (which is unit elastic)
(b) 10/35 ÷ ­2/3
= 10/35 × 3/­2
= 30/­70
= ­0.43 (which is inelastic)
The elasticity decreases as you move down a straight-line demand curve.
Given Qd = 60 ­ 15P + P˛, calculate the (point) price elasticity of demand at a price of:
a. 5
b. 2
c. 0.
Given that:
Qd = 60 ­ 15P + P˛
Then,
dQ/dP = ­15 + 2P.
Thus using the formula, Pεd = dQ/dP × P/Q, the elasticity at the each of the above price points
Equals:
(a) (­15 + (2 × 5)) × (5/ (60 ­ (15 × 5) + 5˛))
= ­5 × 5/10 = ­2.5
(b) (­15 + (2 × 2)) × (2/ (60 ­ (15 × 2) + 2˛))
= ­11 × 2/34 = ­0.65
(c) (­15 + (2 × 0)) × (0/ (60 ­ (15 × 0) + 0˛))
= ­15 × 0/60 = 0
As you move down a straight-line demand curve, what happens to elasticity? Why?
It decreases. P/Q gets less and less, but dQ/dP remains constant.
Given the following supply schedule:
2
4
6
8
10
P
0
10
20
30
40
Q
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Introduction to Economics ­ECO401
VU
a. Draw the supply curve.
b. Using the arc method calculate price elasticity of supply:
i. Between P = 2 and P = 4;
ii. Between P = 8 and P = 10
c. Using the point method calculate price elasticity of supply at P = 6.
d. Does the elasticity of the supply curve increase or decrease as P and Q
increase? Why?
e. What would be the answer to (d) if the supply curve had been a straight line but
intersecting the horizontal axis to the right of the origin?
a. The supply curve will be an upward sloping straight line crossing the vertical axis
where P = 2.
b. Using the formula ΔQ/average Q ÷ ΔP/average P, gives:
10/5 ÷ 2/3= 3
10/35 ÷ 2/9= 1.29
c. Using the formula dQ/dP × P/Q, and given that dQ/dP = 5 (= 10/2), gives:
5 × 6/20= 1.5
d. The elasticity of supply decreases as P and Q increase. It starts at infinity where the
supply curve crosses the vertical axis (Q = 0 and thus P/Q =).
e. No. At the point where it crossed the horizontal axis, the elasticity of supply would be
zero (P = 0 and thus P/Q = 0). Thereafter, as P and Q increased, so would the
elasticity of supply.
Which are likely to have the highest cross elasticity of demand: two brands of tea, or
tea and coffee?
Two brands of tea, because they are closer substitutes than tea and coffee.
Supply tends to be more elastic in the long run than in the short run. Assume that a tax
is imposed on a good that was previously untaxed. How will the incidence of this tax
change as time passes? How will the incidence be affected if demand too becomes
more elastic over time?
As supply becomes more elastic, so output will fall and hence tax revenue will fall. At the
same time price will tend to rise and hence the incidence will shift from the producer to the
consumer.
As demand becomes more elastic, so this too will lead to a fall in sales. This, however, will
have the opposite effect on the incidence of the tax: the burden will tend to shift from the
consumer to the producer.
If raising the tax rate on cigarettes raise more revenue and reduce smoking, are there
any conflict between the health and revenue objectives of the government?
There may still be a dilemma in terms of the amount by which the tax rate should be raised.
To raise the maximum amount of revenue may require only a relatively modest increase in the
tax rate. To obtain a large reduction in smoking, however, may require a very large increase
in the tax rate. Ultimately, if the tax rate were to be so high as to stop people smoking
altogether, there would be no tax revenue at all for the government!
You are a government minister; what arguments might you put forward in favour of
maximising the revenue from cigarette taxation?
That it is better than putting the taxes on more socially desirable activities. That there is the
beneficial spin-off from reducing a harmful activity. (You would conveniently ignore the option
of putting up taxes beyond the point that maximises revenue and thus cutting down even more
on smoking.)
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Introduction to Economics ­ECO401
VU
You are a doctor; why might you suggest that smoking should be severely restricted?
What methods would you advocate?
That the medical arguments concerning damage to health should take precedence over
questions of raising revenue. You would probably advocate using whatever method was most
effective in reducing smoking. This would probably include a series of measures from large
increases in taxes, to banning advertising, to education campaigns against smoking. You
might even go so far as to advocate making smoking tobacco illegal. The problem here, of
course, would be in policing the law.
Why is the supply curve for food often drawn as a vertical straight line?
It is because; the supply of food is virtually fixed in the short run. Once a crop is grown and
harvested, then it is of a fixed amount. (In practice, the timing of releasing crops on to the
market can vary, given that many crops can be stored. This does allow some variation of
supply with price.)
The income elasticity of demand for potatoes is negative (an `inferior' good). What is
the implication of this for potato producers?
Potato producers would expect to earn less as time goes past, given that national income rises
over time. Thus if the incomes of individual potato producers are to be protected, production
should be reduced (with some potato dairy farmers switching to other foodstuffs or away from
food production altogether).
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Table of Contents:
  1. INTRODUCTION TO ECONOMICS:Economic Systems
  2. INTRODUCTION TO ECONOMICS (CONTINUED………):Opportunity Cost
  3. DEMAND, SUPPLY AND EQUILIBRIUM:Goods Market and Factors Market
  4. DEMAND, SUPPLY AND EQUILIBRIUM (CONTINUED……..)
  5. DEMAND, SUPPLY AND EQUILIBRIUM (CONTINUED……..):Equilibrium
  6. ELASTICITIES:Price Elasticity of Demand, Point Elasticity, Arc Elasticity
  7. ELASTICITIES (CONTINUED………….):Total revenue and Elasticity
  8. ELASTICITIES (CONTINUED………….):Short Run and Long Run, Incidence of Taxation
  9. BACKGROUND TO DEMAND/CONSUMPTION:CONSUMER BEHAVIOR
  10. BACKGROUND TO DEMAND/CONSUMPTION (CONTINUED…………….)
  11. BACKGROUND TO DEMAND/CONSUMPTION (CONTINUED…………….)The Indifference Curve Approach
  12. BACKGROUND TO DEMAND/CONSUMPTION (CONTINUED…………….):Normal Goods and Giffen Good
  13. BACKGROUND TO SUPPLY/COSTS:PRODUCTIVE THEORY
  14. BACKGROUND TO SUPPLY/COSTS (CONTINUED…………..):The Scale of Production
  15. BACKGROUND TO SUPPLY/COSTS (CONTINUED…………..):Isoquant
  16. BACKGROUND TO SUPPLY/COSTS (CONTINUED…………..):COSTS
  17. BACKGROUND TO SUPPLY/COSTS (CONTINUED…………..):REVENUES
  18. BACKGROUND TO SUPPLY/COSTS (CONTINUED…………..):PROFIT MAXIMISATION
  19. MARKET STRUCTURES:PERFECT COMPETITION, Allocative efficiency
  20. MARKET STRUCTURES (CONTINUED………..):MONOPOLY
  21. MARKET STRUCTURES (CONTINUED………..):PRICE DISCRIMINATION
  22. MARKET STRUCTURES (CONTINUED………..):OLIGOPOLY
  23. SELECTED ISSUES IN MICROECONOMICS:WELFARE ECONOMICS
  24. SELECTED ISSUES IN MICROECONOMICS (CONTINUED……………)
  25. INTRODUCTION TO MACROECONOMICS:Price Level and its Effects:
  26. INTRODUCTION TO MACROECONOMICS (CONTINUED………..)
  27. INTRODUCTION TO MACROECONOMICS (CONTINUED………..):The Monetarist School
  28. THE USE OF MACROECONOMIC DATA, AND THE DEFINITION AND ACCOUNTING OF NATIONAL INCOME
  29. THE USE OF MACROECONOMIC DATA, AND THE DEFINITION AND ACCOUNTING OF NATIONAL INCOME (CONTINUED……………..)
  30. MACROECONOMIC EQUILIBRIUM & VARIABLES; THE DETERMINATION OF EQUILIBRIUM INCOME
  31. MACROECONOMIC EQUILIBRIUM & VARIABLES; THE DETERMINATION OF EQUILIBRIUM INCOME (CONTINUED………..)
  32. MACROECONOMIC EQUILIBRIUM & VARIABLES; THE DETERMINATION OF EQUILIBRIUM INCOME (CONTINUED………..):The Accelerator
  33. THE FOUR BIG MACROECONOMIC ISSUES AND THEIR INTER-RELATIONSHIPS
  34. THE FOUR BIG MACROECONOMIC ISSUES AND THEIR INTER-RELATIONSHIPS (CONTINUED…….)
  35. THE FOUR BIG MACROECONOMIC ISSUES AND THEIR INTER-RELATIONSHIPS (CONTINUED…….):Causes of Inflation
  36. THE FOUR BIG MACROECONOMIC ISSUES AND THEIR INTER-RELATIONSHIPS (CONTINUED…….):BALANCE OF PAYMENTS
  37. THE FOUR BIG MACROECONOMIC ISSUES AND THEIR INTER-RELATIONSHIPS (CONTINUED…….):GROWTH
  38. THE FOUR BIG MACROECONOMIC ISSUES AND THEIR INTER-RELATIONSHIPS (CONTINUED…….):Land
  39. THE FOUR BIG MACROECONOMIC ISSUES AND THEIR INTER-RELATIONSHIPS (CONTINUED…….):Growth-inflation
  40. FISCAL POLICY AND TAXATION:Budget Deficit, Budget Surplus and Balanced Budget
  41. MONEY, CENTRAL BANKING AND MONETARY POLICY
  42. MONEY, CENTRAL BANKING AND MONETARY POLICY (CONTINUED…….)
  43. JOINT EQUILIBRIUM IN THE MONEY AND GOODS MARKETS: THE IS-LM FRAMEWORK
  44. AN INTRODUCTION TO INTERNATIONAL TRADE AND FINANCE
  45. PROBLEMS OF LOWER INCOME COUNTRIES:Poverty trap theories: