Dr. Mahmoud A. Arafa Elasticity. Income positive negative. Cross positive negative

Similar documents
Law of Supply. General Economics

Unit 1 DEMAND AND SUPPLY ANALYSIS

Lesson-9. Elasticity of Supply and Demand

Copyright 2010 Pearson Education Canada

not to be republished NCERT Chapter 6 Non-competitive Markets 6.1 SIMPLE MONOPOLY IN THE COMMODITY MARKET

The law of supply states that higher prices raise the quantity supplied. The price elasticity of supply measures how much the quantity supplied

07. Engel s Law of family expenditure and significance. - Consumer's surplus estimation and applications.

1.2.3 Price, Income and Cross Elasticities of Demand

Formula: Price of elasticity of demand= Percentage change in quantity demanded Percentage change in price

2007 Thomson South-Western

AP Microeconomics Chapter 6 Outline

Elasticity and Its Applications. Copyright 2004 South-Western

Economic Analysis for Business Decisions Multiple Choice Questions Unit-2: Demand Analysis

Elasticity and Taxation

WJEC (Eduqas) Economics A-level

Chapter 6 Lecture - Elasticity: The Responsiveness of Demand and Supply

Chapter 6 Elasticity: The Responsiveness of Demand and Supply

ECON 101 Introduction to Economics1


Elasticity and Its Applications

Figure 4 1 Price Quantity Quantity Per Pair Demanded Supplied $ $ $ $ $10 2 8

DEMAND ANALYSIS. Samir K Mahajan, M.Sc, Ph.D.,UGC-NET Assistant Professor (Economics)

Chapter 6. Elasticity

Graded exercise questions. Level (I, ii, iii)

Chapter 6 Elasticity: The Responsiveness of Demand and Supply

Economics. In an economy, the production units are called (a) Firm (b) Household (c) Government (d) External Sector

Q.1 Distinguish between increase in demand and increase in quantity demanded of a commodity.

Chapter 3. Table of Contents. Introduction. Empirical Methods for Demand Analysis

UNIT-I INTRODUCTION TO MANAGERIAL ECONOMICS & DEMAND ANALYSIS. Economics as the study of nature and uses of national wealth.

Ch. 7 outline. 5 principles that underlie consumer behavior

E.C.O.-6 Economic Theory

Elasticity: A Measure of Responsiveness. 1 of of 42

Question Paper Business Economics I (MB1B3): January 2009

Sample Paper-05 ( ) Economics Class XII. Time allowed: 3 hours Maximum Marks: 100

DEMAND ANALYSIS. Samir K Mahajan, M.Sc, Ph.D.,UGC-NET Assistant Professor (Economics)

Chapter 2: The Basic Theory Using Demand and Supply. Multiple Choice Questions

EC1010 Introduction to Micro Economics (Econ 6003)

Principles of MicroEconomics: Econ102

Chapter 2 Market analysis

Study Unit 1. Elasticity SIM University. All rights reserved. Introduction

Answers to RSPL/2. Section - A

Chapter 3 Quantitative Demand Analysis

Introduction. Consumer Choice 20/09/2017

The Concept of Elasticity. The Elasticity of Demand. Laugher Curve. The Concept of Elasticity. Sign of Price Elasticity.

Polar Cases of Elasticity and Constant Elasticity

2013 Pearson. What do you do when the price of gasoline rises?

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

FAQ: Supply and Demand

CHAPTER 2: DEMAND AND SUPPLY

Demand and Supply: The Basics

Elasticity of Demand

Introduction Question Bank

EC101 DD/EE PRACTICE Midterm 1 October 3, 2017 Version 09

Elasticity and Its Applications PRINCIPLES OF ECONOMICS (ECON 210) BEN VAN KAMMEN, PHD

ELASTICITY. Chapt er. Key Concepts

Micro Lecture 5: Elasticity Basics

Amherst College Department of Economics Economics 111 Section 3 Fall 2012 Monday, September 17 Lecture: Elasticity

Chapter 4: Understanding Demand

2013 sample MC questions - 90

ECON 1000 D. Come to the PASS workshop with your mock exam complete. During the workshop you can work with other students to review your work.

Managerial Economics

ECONOMICS. Paper 3 : Fundamentals of Microeconomic Theory Module 28 : Non collusive and Collusive model

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. FIGURE 1-2

Interpreting Price Elasticity of Demand

Econ Principles of Microeconomics - Assignment 1

ECONOMICS OF BUSINESS AND FINANCE

(per day) Pizzas. Figure 1

Chapter 4 DEMAND. Essential Question: How do we decide what to buy?

1. T F The resources that are available to meet society s needs are scarce.

Text transcription of Chapter 4 The Market Forces of Supply and Demand

MICROECONOMICS SECTION I. Time - 70 minutes 60 Questions

1) Your answer to this question is what form of the exam you had. The answer is A if you have form A. The answer is B if you have form B etc.

Introduction. Learning Objectives. Learning Objectives. Economics Today Twelfth Edition. Chapter 20 Demand and Supply Elasticity

Chapter 2 The Basics of Supply and Demand

1 of 14 5/1/2014 4:56 PM

Subtleties of the Supply and Demand Model: Price Floors, Price Ceilings, and Elasticity

CHAPTER THREE DEMAND AND SUPPLY

9/24/2008. Utility. Utility and Consumer Demand. Law of DMU. Measuring Utility. Income Effect. Scarcity is our lot

PART: A Introductory Micro Economics Capsules UNIT: I TOPIC: INTRODUCTION

Understanding Supply Factors and Agricultural Products

Lecture 6 Consumer Choice

GOVERNMENT OF KARNATAKA SCHEME OF VALUATION. Subject Code : 22 ENGLISH VERSION Subject : ECONOMICS

Commerce 295 Midterm Answers

ECO 100Y L0201 INTRODUCTION TO ECONOMICS. Midterm Test #1

Chapter 2 Supply and Demand

Elasticity. Shape of the Demand Curve

Econ 2113: Principles of Microeconomics. Spring 2009 ECU

2014 $1.75 $10.00 $ $1.50 $10.50 $ $1.65 $11.00 $ $2.00 $11.50 $150

6) The mailing must be postmarked by June 15. 7) If you have any questions please me at

.the key ideas. Webnote 122

Perfect competition: occurs when none of the individual market participants (ie buyers or sellers) can influence the price of the product.

AS/ECON AF Answers to Assignment 1 October 2007

ECONOMICS ASSIGNMENT CLASS XII MICRO ECONOMICS UNIT I INTRODUCTION. 4. Is free medicine given to patients in Govt. Hospital a scarce commodity?

Monopoly. 3 Microeconomics LESSON 5. Introduction and Description. Time Required. Materials

PRINCIPLES OF ECONOMICS PAPER 3 RD

Case: An Increase in the Demand for the Product

ELASTICITY AND ITS APPLICATION. J. Mao

Exam Spring. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.

Individual and Market Demand

CH 5 sample questions - 80

Transcription:

Introduction: When the price of a goods falls, its quantity demanded rises and when the price of the goods rises, its quantity demanded falls. This is generally known as law of demand. This law of demand indicates only the direction of change in quantity demanded in response to change in price. This does not tell us by how much or to what extent the quantity demanded of goods will change in response to a change in: its price, Consumer Income, or Price of other goods. This information as to how much or to what extent the quantity demanded of a good will change as a result of a change in its price, Consumer Income, or Price of other goods is provided by the concept of elasticity of demand. The concept of elasticity has a very great importance in economic theory as well as for formulation of suitable economic policy. Definitions: We can define elasticity according to many factors affecting demand. In general, lasticity of Demand refers to the degree of responsiveness of quantity demanded to the changes in the determinants of demand. There are mainly three quantifiable determinants of demand: rice of the Good; Income of the Consumer; and Price of the Related Goods. Then we have three concepts of elasticity: Price, Income, and Cross lasticity of Demand. Price elasticity of Demand is the degree of responsiveness of demand to a change in its price. In technical terms it is the ratio of the percentage change in demand to the percentage change in price, keeping all other things constant. Income elasticity of demand refers to the sensitivity of the quantity demanded for a certain good to a change in real income of consumers who buy this good, keeping all other things constant. Cross elasticity of demand is an economic concept that measures the responsiveness in the quantity demand of one good when a change in price takes place in another good. Supply Price lastic Inelastic perfectly elastic perfectly inelastic unit elastic lasticity Demand Income positive negative Cross positive negative Price lasticity of Demand: Price elasticity of demand is a measure of the relationship between a change in the quantity demanded of a particular good and a change in its price. Price elasticity of demand is a term in economics often used when discussing price sensitivity. The formula for calculating price elasticity of demand is: - 1 -

Price lasticity of Demand = % Change in Quantity Demanded / % Change in Price % Qd p % P Q d % Qd Qd % P P P p % % Qd Q Q 2 1 Q Q d d Q P P P P 2 1 P P The four Important Methods of Measuring Price lasticity of Demand: There are four methods of measuring elasticity of demand. They are the percentage method, point method, arc method and expenditure method. 1- The Percentage Method: The price elasticity of demand is measured by its coefficient p. This coefficient p measures the percentage change in the quantity of a commodity demanded resulting from a given percentage change in its price: Thus p % Q Q d d P * % P P Q d Where q refers to quantity demanded p to price and to change. If p > 1, demand is elastic. If p < 1, demand is inelastic, it p = 1 demand is unitary elastic. With this formula, we can compute price elasticities of demand on the basis of a demand schedule. Table: Demand Schedule: Combination Price (Rs.) per Kg. of X Quantity Kgs. of X A 6 0 B 5-10 C 4 20 D 3-30 2 40 F 1 50 G 0 60-2 -

Let us first take combinations B and D. 1--- Suppose the price of commodity X falls from Rs. 5 per kg to Rs. 3 per kg and its quantity demanded increases from 10 kgs to 30 kgs, Then p % Qd 30 10 5 * 5 1 % P 3 5 10 This shows elastic demand or elasticity of demand greater than unitary. Note: The formula can be understood like this: q =q 2 q 1 where <7 2 is the new quantity (30 kgs.) and q 1 the original quantity (10 kgs.) p p 2 P 1 where p 2 is the new price (Rs. 3) and <$p sub 1> the original price (Rs. 5) In the formula, p refers to the original price (p,) and q to original quantity (q 1 ). The opposite is the case in example (2) below, where Rs. 3 becomes the original price and 30 kgs. as the original quantity. 2--- Let us measure elasticity by moving in the reverse direction. Suppose the price of X rises from Rs. 3 per kg. to Rs. 5 per kg. and the quantity demanded decreases from 30 kgs. to 10 kgs. Then p % Qd 10 30 3 * 1 1 % P 5 3 30 This shows unitary elasticity of demand. Notice that the value of p in example (2) differs from that in example (1) depending on the direction in which we move. This difference in the elasticities is due to the use of a different base in computing percentage changes in each case. Now consider combinations D and F. 3--- Suppose the price of commodity X falls from Rs. 3 per kg. to Re. 1 per kg. and its quantity demanded increases from 30 kgs. to 50 kgs. Then p % Qd 50 30 3 * 1 1 % P 1 3 30 This is again unitary elasticity. 4--- Take the reverse order when the price rises from Re. 1 per kg. to Rs. 3 per kg. and the quantity demanded decreases from 50 kgs. to 30 kgs. Then p % Qd 30 50 1 1 * 1 % P 3 1 50 5 This shows inelastic demand or less than unitary. - 3 -

The value of p again differs in this example than that given in example (3) for the reason stated above. (2) The Point Method: Prof. Marshall devised a geometrical method for measuring elasticity at a point on the demand curve. Let RS be a straight line demand curve in Figure. If the price falls from PB (= OA) to MD (= OC). The quantity demanded increases from OB to OD. lasticity at point P on the RS demand curve according to the formula is: p = q/ p x p/q Where q represents changes in quantity demanded p changes in price level while p and q are initial price and quantity levels. From Figure: q = BD = QM p = PQ p = PB q = OB Substituting these values in the elasticity formula: With the help of the point method, it is easy to point out the elasticity at any point along a demand curve. Suppose that the straight line demand curve DC in Figure below is 6 centimeters. - 4 -

Five points L, M, N, P and Q are taken oh this demand curve. The elasticity of demand at each point can be known with the help of the above method. Let point N be in the middle of the demand curve. So elasticity of demand at point: We arrive at the conclusion that at the mid-point on the demand curve the elasticity of demand is unity. Moving up the demand curve from the mid-point, elasticity becomes greater. When the demand curve touches the Y-axis, elasticity is infinity. Ipso facto, any point below the mid-point towards the X-axis will show elastic demand. lasticity becomes zero when the demand curve touches the X-axis. (3) The Arc Method: We have studied the measurement of elasticity at a point on a demand curve. But when elasticity is measured between two points on the same demand curve, it is known as arc elasticity. In the words of Prof. Baumol, Arc elasticity is a measure of the average responsiveness to price change exhibited by a demand curve over some finite stretch of the curve. Any two points on a demand curve make an arc. The area between P and M on the DD curve in Figure below is an arc which measures elasticity over a certain range of price and quantities. On any two points of a demand curve the elasticity coefficients are likely to be different depending upon the method of computation. Consider the price-quantity combinations P and M as given in Table below. - 5 -

Table: Demand Schedule: Point Price (Rs.) Quantity (Kg) P 8 10 M 6 12 If we move from P to M, the elasticity of demand is: p % Qd 12 10 8 4 * 1 % P 6 8 10 5 If we move in the reverse direction from M to P, then p 10 12 6 1 * 1 8 6 12 2 Thus the point method of measuring elasticity at two points on a demand curve gives different elasticity coefficients because we used a different base in computing the percentage change in each case. To avoid this discrepancy, elasticity for the arc (PM in Figure above) is calculated by taking the average of the two prices [(p 1, + p 2 1/2] and the average of the two quantities [(p 1, + q 2 ) 1/2]. The formula for price elasticity of demand at the mid-point (C in Figure above) of the arc on the demand curve is p Qd ( q q )/2 Q ( p p )/2 Q ( p p ) 1 2 d 1 2 d 1 2 * * P ( q q )/2 P P ( q q ) 1 2 1 2 ( p p )/2 1 2 On the basis of this formula, we can measure arc elasticity of demand when there is a movement either from point P to M or from M to P. From P to M at P, p 1 = 8, q 1, =10, and at M, P 2 = 6, q 2 = 12 Applying these values, we get - 6 -

Thus whether we move from M to P or P to M on the arc PM of the DD curve, the formula for arc elasticity of demand gives the same numerical value. The closer the two points P and M are, the more accurate is the measure of elasticity on the basis of this formula. If the two points which form the arc on the demand curve are so close that they almost merge into each other, the numerical value of arc elasticity equals the numerical value of point elasticity. (4) The Total Outlay Method: Marshall evolved the total outlay, total revenue or total expenditure method as a measure of elasticity. By comparing the total expenditure of a purchaser both before and after the change in price, it can be known whether his demand for a good is elastic, unity or less elastic. Total outlay is price multiplied by the quantity of a good purchased: Total Outlay = Price x Quantity Demanded. This is explained with the help of the demand schedule in Table below. (i) lastic Demand: Demand is elastic, when with the fall in price the total expenditure increases and with the rise in price the total expenditure decreases. Table 11.3 shows that when the price falls from Rs. 9 to Rs. 8, the total expenditure increases from Rs. 180 to Rs. 240 and when price rises from Rs. 7 to Rs. 8, the total expenditure falls from Rs. 280 to Rs. 240. Demand is elastic ( p > 1) in this case. (ii) Unitary lastic Demand: When with the fall or rise in price, the total expenditure remains unchanged; the elasticity of demand is unity. This is shown in the Table when with the fall in price from Rs. 6 to Rs. 5 or with the rise in price from Rs. 4 to Rs. 5, the total expenditure remains unchanged at Rs. 300, i.e., p = 1. (iii) Less lastic Demand: - 7 -

Demand is less elastic if with the fall in price the total expenditure falls and with the rise in price the total expenditure rises. In the Table when the price falls from Rs. 3 to Rs. 2 total expenditure falls from Rs. 240 to Rs. 180, and when the price rises from Re. 1 to Rs. 2 the total expenditure also rises from Rs. 100 to Rs. 180. This is the case of inelastic or less elastic demand, p < 1. Table below summarises these relationships: Table: Total Outlay Method: Price ТЕ p Falls Rises >> 1 Rises Falls Falls Unchanged = 1 Rises Unchanged Falls Falls Rises Rises << 1 Figure below illustrates the relation between elasticity of demand and total expenditure. The rectangles show total expenditure: Price x quantity demanded. The figure shows that at the midpoint of the demand curve, total expenditure is maximum in the range of unitary elasticity, i.e. Rs. 6, Rs. 5 and Rs. 4 with quantities 50 kgs., 60 kgs. and 75 kgs.. Total expenditure rises as price falls, in the elastic range of demand, i.e. Rs. 9, Rs. 8 and Rs. 7 with quantities 20 kgs., 30 kgs. and 40 kgs. Total expenditure falls as price falls in the elasticity range, i.e. Rs.3, Rs. 2 and Re. 1 with quantities 80 kgs., 90 kgs. and 100 kgs. Thus elasticity of demand is unitary in the AB range of DD, curve, elastic in the range AD above point A and less elastic in the BD 1 range below point B. The conclusion is that price elasticity of demand refers to a movement along a specific demand curve. Types of Price lasticity of Demand: The extent of responsiveness of demand with change in the price is not always the same. The demand for a product can be elastic or inelastic, depending on the rate of change in the demand with respect to change in price of a product. - 8 -

lastic demand is the one when the response of demand is greater with a small proportionate change in the price. On the other hand, inelastic demand is the one when there is relatively a less change in the demand with a greater change in the price. For better understanding the concepts of elastic and inelastic demand, the price elasticity of demand has been divided into five types, which are shown in Figure below: Types of Price lasticity of Demand Perfectly lastic Perfectly Inelastic Relatively lastic Relatively Inelastic Unitary lastic 1. Perfectly lastic Demand: When a small change in price of a product causes a major change in its demand, it is said to be perfectly elastic demand. In perfectly elastic demand, a small rise in price results in fall in demand to zero, while a small fall in price causes increase in demand to infinity. In such a case, the demand is perfectly elastic or e p = 00. The degree of elasticity of demand helps in defining the shape and slope of a demand curve. Therefore, the elasticity of demand can be determined by the slope of the demand curve. Flatter the slope of the demand curve, higher the elasticity of demand. In perfectly elastic demand, the demand curve is represented as a horizontal straight line, which is shown in Figure below: From Figure it can be interpreted that at price OP, demand is infinite; however, a slight rise in price would result in fall in demand to zero. It can also be interpreted from Figure that at price P consumers are ready to buy as much quantity of the product as they want. However, a small rise in price would resist consumers to buy the product. - 9 -

Though, perfectly elastic demand is a theoretical concept and cannot be applied in the real situation. However, it can be applied in cases, such as perfectly competitive market and homogeneity products. In such cases, the demand for a product of an organization is assumed to be perfectly elastic. From an organization s point of view, in a perfectly elastic demand situation, the organization can sell as much as much as it wants as consumers are ready to purchase a large quantity of product. However, a slight increase in price would stop the demand. 2. Perfectly Inelastic Demand: A perfectly inelastic demand is one when there is no change produced in the demand of a product with change in its price. The numerical value for perfectly inelastic demand is zero (e p =0). In case of perfectly inelastic demand, demand curve is represented as a straight vertical line, which is shown in Figure below: It can be interpreted from Figure-3 that the movement in price from OP1 to OP2 and OP2 to OP3 does not show any change in the demand of a product (OQ). The demand remains constant for any value of price. Perfectly inelastic demand is a theoretical concept and cannot be applied in a practical situation. However, in case of essential goods, such as salt, the demand does not change with change in price. Therefore, the demand for essential goods is perfectly inelastic. 3. Relatively lastic Demand: Relatively elastic demand refers to the demand when the proportionate change produced in demand is greater than the proportionate change in price of a product. The numerical value of relatively elastic demand ranges between one to infinity. Mathematically, relatively elastic demand is known as more than unit elastic demand (e p >1). For example, if the price of a product increases by 20% and the demand of the product decreases by 25%, then the demand would be relatively elastic. The demand curve of relatively elastic demand is gradually sloping, as shown in Figure below: - 11 -

It can be interpreted from Figure-4 that the proportionate change in demand from OQ1 to OQ2 is relatively larger than the proportionate change in price from OP1 to OP2. Relatively elastic demand has a practical application as demand for many of products respond in the same manner with respect to change in their prices. For example, the price of a particular brand of cold drink increases from Rs. 15 to Rs. 20. In such a case, consumers may switch to another brand of cold drink. However, some of the consumers still consume the same brand. Therefore, a small change in price produces a larger change in demand of the product. 4. Relatively Inelastic Demand: Relatively inelastic demand is one when the percentage change produced in demand is less than the percentage change in the price of a product. For example, if the price of a product increases by 30% and the demand for the product decreases only by 10%, then the demand would be called relatively inelastic. The numerical value of relatively elastic demand ranges between zero to one (e p <1). Marshall has termed relatively inelastic demand as elasticity being less than unity. The demand curve of relatively inelastic demand is rapidly sloping, as shown in Figure below: It can be interpreted from Figure-5 that the proportionate change in demand from OQ1 to OQ2 is relatively smaller than the proportionate change in price from OP1 to OP2. Relatively inelastic demand has a practical application as demand for many of products respond in the same manner with respect to change in their prices. Let us understand the implication of relatively inelastic demand with the help of an example. xample: The demand schedule for milk is given in Table below: Calculate the price elasticity of demand and determine the type of price elasticity. - 11 -

Solution: P= 15, Q = 100, P1 = 20, Q1 = 90 Therefore, change in the price of milk is: P = P1 P P = 20 15 P = 5 Similarly, change in quantity demanded of milk is: Q = Q1 Q Q = 90 100 Q = -10 The change in demand shows a negative sign, which can be ignored. This is because of the reason that the relationship between price and demand is inverse that can yield a negative value of price or demand. Price elasticity of demand for milk is: e p = Q/ P * P/Q e p = 10/5 * 15/100 e p = 0.3 The price elasticity of demand for milk is 0.3, which is less than one. Therefore, in such a case, the demand for milk is relatively inelastic. 5. Unitary lastic Demand: When the proportionate change in demand produces the same change in the price of the product, the demand is referred as unitary elastic demand. The numerical value for unitary elastic demand is equal to one (e p =1). The demand curve for unitary elastic demand is represented as a rectangular hyperbola, as shown in Figure below: From Figure-6, it can be interpreted that change in price OP1 to OP2 produces the same change in demand from OQ1 to OQ2. Therefore, the demand is unitary elastic. The different types of price elasticity of demand are summarized in Table below: - 12 -

Income lasticity of Demand: Income elasticity of demand is the degree of responsiveness of quantity demanded of a commodity due to change in consumer s income, other things remaining constant. In other words, it measures by how much the quantity demanded changes with respect ot the change in income. The income elasticity of demand is defined as the percentage change in quantity demanded due to certain percent change in consumer s income. Where, Y = lasticity of demand q = Original quantity demanded q = Change in quantity demanded y = Original consumer s income y= Change in consumer s income xample to xplain Income lasticity of Demand: Suppose that the initial income of a person is Rs.2000 and quantity demanded for the commodity by him is 20 units. When his income increases to Rs.3000, quantity demanded by him also increases to 40 units. Find out the income elasticity of demand. Solution: Here, q = 100 units q = (40-20) units = 20 units - 13 -

y = Rs.2000 y =Rs. (3000-2000) =Rs.1000 Now, Hence, an increase of Rs.1000 in income i.e. 1% in income leads to a rise of 2% in quantity demanded. Types of Income lasticity of demand: 1. Positive income elasticity of demand ( Y >0) If there is direct relationship between income of the consumer and demand for the commodity, then income elasticity will be positive. That is, if the quantity demanded for a commodity increases with the rise in income of the consumer and vice versa, it is said to be positive income elasticity of demand. For example: as the income of consumer increases, they consume more of superior (luxurious) goods. On the contrary, as the income of consumer decreases, they consume less of luxurious goods. Positive income elasticity can be further classified into three types: Income elasticity greater then unity ( Y > 1) If the percentage change in quantity demanded for a commodity is greater than percentage change in income of the consumer, it is said to be income greater than unity. For example: When the consumer s income rises by 3% and the demand rises by 7%, it is the case of income elasticity greater than unity. In the given figure, quantity demanded and consumer s income is measured along X-axis and Y- axis respectively. The small rise in income from OY to OY 1 has caused greater rise in the quantity demanded from OQ to OQ 1 and vice versa. Thus, the demand curve DD shows income elasticity greater than unity. Income elasticity equal to unity ( Y = 1) - 14 -

If the percentage change in quantity demanded for a commodity is equal to percentage change in income of the consumer, it is said to be income elasticity equal to unity. For example: When the consumer s income rises by 5% and the demand rises by 5%, it is the case of income elasticity equal to unity. In the given figure, quantity demanded and consumer s income is measured along X-axis and Y- axis respectively. The small rise in income from OY to OY 1 has caused equal rise in the quantity demanded from OQ to OQ 1 and vice versa. Thus, the demand curve DD shows income elasticity equal to unity. Income elasticity less then unity ( Y < 1) If the percentage change in quantity demanded for a commodity is less than percentage change in income of the consumer, it is said to be income greater than unity. For example: When the consumer s income rises by 5% and the demand rises by 3%, it is the case of income elasticity less than unity. In the given figure, quantity demanded and consumer s income is measured along X-axis and Y- axis respectively. The greater rise in income from OY to OY 1 has caused small rise in the quantity demanded from OQ to OQ 1 and vice versa. Thus, the demand curve DD shows income elasticity less than unity. 2. Negative income elasticity of demand ( Y <0): If there is inverse relationship between income of the consumer and demand for the commodity, then income elasticity will be negative. That is, if the quantity demanded for a commodity decreases with the rise in income of the consumer and vice versa, it is said to be negative income - 15 -

elasticity of demand. For example: As the income of consumer increases, they either stop or consume less of inferior goods. In the given figure, quantity demanded and consumer s income is measured along X-axis and Y- axis respectively. When the consumer s income rises from OY tooy1 the quantity demanded of inferior goods falls from OQ to OQ 1 and vice versa. Thus, the demand curve DD shows negative income elasticity of demand. 3. Zero income elasticity of demand ( Y =0): If the quantity demanded for a commodity remains constant with any rise or fall in income of the consumer and, it is said to be zero income elasticity of demand. For example: In case of basic necessary goods such as salt, kerosene, electricity, etc. there is zero income elasticity of demand. In the given figure, quantity demanded and consumer s income is measured along X-axis and Y- axis respectively. The consumer s income may fall to OY 1 or rise to OY 2 from OY, the quantity demanded remains the same at OQ. Thus, the demand curve DD, which is vertical straight line parallel to Y-axis shows zero income elasticity of demand. Uses of Income lasticity of Demand in Business Decision Making: Any products that are manufactured by the producers can be classified into two types normal goods and inferior goods. Normal goods Goods whose demand is directly proportional to the income of the consumers are known as normal goods. Simply, goods whose demand rises with rise in income and whose demand falls with fall in income is known as normal goods e.g jewelry. The coefficient of income elasticity of these goods is always positive. Inferior goods Goods whose demand is inversely proportional to the income of the consumers are known as inferior goods. - 16 -

In other words, inferior goods are such goods whose demand falls with rise in income and vice versa e.g. budget smartphones. The coefficient of income elasticity of these goods is always negative. Knowledge about the nature of products is important to any producers in order to make further decisions related to the goods in right manner. To know about stage of trade cycle, we have already known that demand of normal goods is directly proportional to the income of consumers while demand of inferior goods is inversely proportional to the income of consumers. We see, people prefer riding public bus when their income is low but with comparatively high income, same people start using cab for transportation. In this situation, public bus is an inferior good while cab is a normal good. Demand for normal goods increases during prosperity and decreases during regression. Conversely, demand for inferior goods increases during regression and decreases during prosperity. However, demands for goods that are necessary in our day to day lives are not much affected during prosperity as well as during regression. For forecasting demand: Income elasticity of demand can be used for predicting future demand of any goods and services in case when manufacturers have knowledge of probable future income of the consumers. For example: Let us suppose, Wheels is a car manufacturing company which manufactures luxury cars as well as small cars. The company has calculated that income elasticity of luxury car (normal good) is +4 while income elasticity of small car (inferior good) is -5. Let us also suppose that the company has undertaken a research and has found that consumer income will rise by 3% in upcoming year. Through the above information, Wheels can forecast by how much the demand of luxury car and small car will undergo change in the upcoming year. This information can save the company a lot of money by preventing overproduction or underproduction. - 17 -

To determine price, Having knowledge of income elasticity of any product is essential in order to correctly price them. Demand of income elastic goods or goods with positive income elasticity tends to fall with fall in income of the demanding consumers. Thus, a reduction in price of the commodity may help in increasing the demand and compensate for the reduction in price by generating more sales and revenue. Cross lasticity of Demand: It is the ratio of proportionate change in the quantity demanded of Y to a given proportionate change in the price of the related commodity X. It is a measure of relative change in the quantity demanded of a commodity due to a change in the price of its substitute/complement. It can be expressed as: cross percentage change in the quantity demanded of Y percentage change in the price of the related commodity X cross % Q % P Y X Cross elasticity may be infinite or zero if the slightest change in the price of X causes a substantial change in the quantity demanded of Y. It is always the case with goods which have perfect substitutes for one another. Cross elasticity is zero, if a change in the price of one commodity will not affect the quantity demanded of the other. In the case of goods which are not related to each other, cross elasticity of demand is zero. Definition: The cross elasticity of demand is the proportional change in the quantity of X good demanded resulting from a given relative change in the price of a related good Y Ferguson. The cross elasticity of demand is a measure of the responsiveness of purchases of Y to change in the price of X Leibafsky. Types of Cross lasticity of Demand: 1. Positive: When goods are substitute of each other than cross elasticity of demand is positive. In other words, an increase in the price of Y leads to an increase in the demand of X. For instance, with the increase in price of tea, demand of coffee will increase. In figure below quantity has been measured on OX-axis and price on OY-axis. At price OP of Y-commodity, demand of X- commodity is OM. Now as price of Y commodity increases to OP 1 demand of X-commodity increases to OM 1 Thus, cross elasticity of demand is positive. - 18 -

2. Negative: In case of complementary goods, cross elasticity of demand is negative. A proportionate increase in price of one commodity leads to a proportionate fall in the demand of another commodity because both are demanded jointly. In figure below quantity has been measured on OX-axis while price has been measured on OY-axis. When the price of commodity increases from OP to OP 1 quantity demanded falls from OM to OM 1. Thus, cross elasticity of demand is negative. 3. Zero: Cross elasticity of demand is zero when two goods are not related to each other. For instance, increase in price of car does not affect the demand of cloth. Thus, cross elasticity of demand is zero. It has been shown in figure below: Therefore, it depends upon substitutability of goods. If substitutability is perfect, cross elasticity is infinite; if on the other hand, substitutability does not exist, cross elasticity is zero. In the case of complementary goods like jointly demanded goods cross elasticity is negative. A rise in the price of one commodity X will mean not only decrease in the quantity of X but also decrease in the quantity demanded of Y because both are demanded together. Measurement of Cross lasticity of Demand: - 19 -

Cross elasticity of demand can be measured by the following formula: The Importance of lasticity of Demand: Some important points from which you can realize the important of price elasticity of demand! Price elasticity of demand is a very important concept. Its importance can be realized from the following points: 1. International trade: In order to fix prices of the goods to be exported, it is important to have knowledge about the elasticity s of demand for such goods. A country may fix higher prices for the products with inelastic demand. However, if demand for such goods in the importing country is elastic, then the exporting country will have to fix lower prices. - 21 -

2. Formulation of Government Policies: The concept of price elasticity of demand is important for formulating government policies, especially the taxation policy. Government can impose higher taxes on goods with inelastic demand, whereas, low rates of taxes are imposed on commodities with elastic demand. 3. Factor Pricing: Price elasticity of demand helps in determining price to be paid to the factors of production. Share of each factor in the national product is determined in proportion to its demand in the productive activity. If demand for a particular factor is inelastic as compared to the other factors, then it will attract more rewards. 4. Decisions of Monopolist: A monopolist considers the nature of demand while fixing price of his product. If demand for the product is elastic, then he will fix low price. However, if demand is inelastic, then he is in a position to fix a high price. 5. Paradox of poverty amidst plenty: A bumper crop, instead of bringing prosperity to farmers, brings poverty. This is called the paradox of poverty amidst plenty. It happens due to inelastic demand for most of the agricultural products. When supply of crops increases as a result of rich harvest, their prices drastically fall due to inelastic demand. As a result, their total income goes down. - 21 -