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GNDU Question Paper-2022
B.A 1
st
Semester
ECONOMICS
(Micro Economics)
Time Allowed: Three Hours Maximum Marks: 100
Note: Attempt Five questions in all, selecting at least One question from each section. The
Fifth question may be attempted from any section. All questions carry equal marks
SECTION-A
1. (a) Discuss nature and scope of Economics.
(b) Explain three methods of measuring price elasticity of demand.
2. (a) Define equilibrium of consumer through cardinal utility analysis, (b) Critically
examine revealed preference hypothesis.
SECTION-B
3. State and explain the law of variable proportions. In which stage of law does a typical
business firm operate?
4. What is meant by total revenue, average revenue and marginal revenue? Discuss the
relationship between AR, MR and Price elasticity of demand.
SECTION-C
(5). What are the characteristics of perfect competition? How is equilibrium of a firm
determined under perfect competition in the short period and long period ?
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6. What is meant by monopolistic competition? How is equilibrium of firm and group
determined under monopolistic competition?
SECTION-D
7. Critically examine the neo-classical marginal productivity theory of distribution.
8. (a) 'Rent is surplus of actual earning over transfer earnings. Discuss.
(b) Explain Knight's uncertainty theory of profit. What objections are raised against it?
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GNDU Answer Paper-2022
B.A 1
st
Semester
ECONOMICS
(Micro Economics)
Time Allowed: Three Hours Maximum Marks: 100
Note: Attempt Five questions in all, selecting at least One question from each section. The
Fifth question may be attempted from any section. All questions carry equal marks
SECTION-A
1. (a) Discuss nature and scope of Economics.
Ans: Introduction:
Imagine a world where resources like food, money, and time are unlimited. Everyone would
have everything they need, and there would be no need to make choices. But in the real
world, resources are limited — and that’s where Economics comes in. Economics is the
study of how individuals, businesses, governments, and societies make choices about using
limited resources to satisfy their unlimited wants.
Let’s understand this subject in a simple and meaningful way, starting with the nature of
economics and then exploring its scope.
✦ Nature of Economics:
The nature of economics refers to what economics is all about — its character, essence, and
fundamental features.
1. Economics is a Social Science:
Economics studies the behavior of human beings in society — how they earn, spend, save,
invest, and consume resources. Just like Sociology or Political Science, it observes human
interactions, but with a focus on wealth and welfare. Since it deals with human behavior,
which can be unpredictable, economics is considered a social science, not a pure science like
Physics or Chemistry.
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Example: A farmer deciding what crops to grow based on market prices is part of
economic behavior.
2. Study of Scarcity and Choice:
The most important feature of economics is that it deals with scarcity — limited resources
like money, raw materials, or time — and how people make choices to use those resources
wisely.
Example: A government with a limited budget must choose whether to spend more on
hospitals or schools.
3. Science of Wealth, Welfare, or Growth:
Over the years, economists have viewed economics differently:
• Adam Smith (Father of Economics) called it the “Science of Wealth” — studying how
nations become rich.
• Alfred Marshall called it the “Science of Welfare” — focusing on how wealth can
improve human well-being.
• Modern economists like Paul Samuelson see it as the science of growth and
development — helping nations grow stronger economically.
Today, economics is all of these together. It is the science of wealth, human welfare,
scarcity, choice, and development.
4. Positive and Normative Science:
• Positive Economics explains things as they are. It answers questions like “What is the
unemployment rate?” or “What happens if prices go up?”
• Normative Economics tells us how things should be. It answers questions like
“Should the government increase minimum wage?” or “Is it fair to tax the rich
more?”
Positive = facts; Normative = opinions or suggestions.
✦ Scope of Economics:
The scope of economics refers to the range of topics it covers. It tells us what all economics
studies. Broadly, it is divided into two major branches:
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1. Microeconomics:
The word “micro” means small. Microeconomics deals with the behavior of individual units
like a person, a family, a firm, or a particular industry.
Example: Studying how a bakery sets the price of its cakes or how a customer chooses
between Pepsi and Coke.
Main topics under microeconomics:
• Demand and Supply
• Price Determination
• Consumer Behavior
• Production and Cost
• Market Structures (Perfect Competition, Monopoly, etc.)
2. Macroeconomics:
“Macro” means large. Macroeconomics looks at the entire economy. It studies the behavior
of economic systems as a whole, such as the economy of a country or the world.
Example: Studying why inflation is rising in India, or how unemployment affects the
GDP.
Main topics under macroeconomics:
• National Income
• Employment and Unemployment
• Inflation and Deflation
• Monetary and Fiscal Policy
• Economic Growth and Development
3. International Economics:
This part studies economic relations between countries, like trade, foreign exchange, and
international financial institutions like the IMF and World Bank.
Example: Why does India import oil from the Middle East? How does the U.S. dollar
affect Indian markets?
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4. Public Finance:
It deals with the income and expenditure of the government. It studies how governments
collect taxes, borrow money, and spend on welfare programs.
5. Development Economics:
This area focuses on how underdeveloped or developing countries can grow economically,
reduce poverty, improve education, and raise the standard of living.
6. Environmental and Agricultural Economics:
Modern economics also studies how to use natural resources wisely and how to improve
agriculture to feed the growing population.
✦ Conclusion:
To sum up, economics is not just about money — it is about life choices. From buying a
chocolate to creating national policies, economics helps us understand the best way to use
resources. Its nature lies in studying human behavior, scarcity, and welfare, and its scope is
vast, covering every area from individual decisions to global trade.
In simple words, economics is the science of decision-making in a world of limited resources
and unlimited desires.
(b) Explain three methods of measuring price elasticity of demand.
Ans: Price Elasticity of Demand (PED) is an important concept in economics that helps us
understand how consumers react to changes in the price of a product. In simple words, it
tells us how much the demand for a product changes when its price changes. If people stop
buying a product when the price rises, we say the demand is elastic. If they still buy it
despite a price change, the demand is inelastic.
Economists have developed several methods to measure the price elasticity of demand,
depending on the type of data and situation. In this answer, we will explain three main
methods used to measure PED:
1. Total Expenditure (or Total Outlay) Method
2. Percentage (or Proportional) Method
3. Point Elasticity Method
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Let us now discuss each of these methods in a simple and easy-to-understand way.
1. Total Expenditure (or Total Outlay) Method
This method was developed by Professor Alfred Marshall, and it is one of the most practical
methods to estimate elasticity. This approach is based on observing changes in total
expenditure (Price × Quantity demanded) when the price of a product changes.
Concept:
We observe how total spending by consumers on a product changes as the price changes.
Based on this, we can judge whether demand is elastic, inelastic, or unitary.
How it works:
• If price decreases and total expenditure increases, demand is elastic.
(Consumers buy more than proportionately, increasing total revenue)
• If price decreases and total expenditure also decreases, demand is inelastic.
(Consumers don’t buy much more, so total revenue falls)
• If price decreases and total expenditure remains the same, demand is unitary elastic.
(The percentage change in quantity demanded exactly equals the percentage change
in price)
Example:
Suppose the price of bananas falls from ₹10 to ₹8 per dozen:
• At ₹10, quantity demanded was 100 dozens → Total expenditure = ₹1000
• At ₹8, quantity demanded becomes 140 dozens → Total expenditure = ₹1120
Since the total expenditure increased as the price decreased, the demand is elastic.
Advantages:
• Simple to understand and calculate.
• Useful when only price and expenditure data are available.
Limitations:
• Does not give the exact numerical value of elasticity.
• Not useful for comparing different products.
2. Percentage (or Proportional) Method
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Also called the Arc Elasticity Method, this is the most common and widely used method in
economics. It uses the percentage change in quantity demanded and the percentage change
in price to calculate elasticity.
Formula:
Where:
• ΔQ = Change in Quantity
• ΔP = Change in Price
• Q = Original Quantity
• P = Original Price
Example:
Let’s say the price of tea increases from ₹20 to ₹25, and as a result, quantity demanded falls
from 200 cups to 150 cups.
Now:
• ΔQ = -50 cups
• ΔP = ₹5
• Q = 200
• P = ₹20
Ignore the minus sign (we know price and demand move in opposite directions). So, Ep =
2.5, which means demand is elastic.
Advantages:
• Provides the exact numerical value of elasticity.
• Helpful for comparing different products or market conditions.
Limitations:
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• Assumes that changes are small and accurate.
• Not suitable when there's a large price or quantity change, as it may give misleading
results.
3. Point Elasticity Method
This method is used when we want to measure elasticity at a particular point on the
demand curve. It is more theoretical and accurate, especially when we are dealing with a
very small change in price or quantity.
Formula:
Here,
• dQ/dP is the derivative or slope of the demand curve.
• P = Price at the point
• Q = Quantity at the point
This method is useful when demand is expressed as a mathematical function, like
Q=100−2P. Economists use calculus to find the exact value of elasticity at a specific price and
quantity.
Example:
Suppose the demand function is:
Q=100−2P
Find elasticity at P = ₹20.
• Q = 100 - 2×20 = 60
• dQ/dP = -2 (from the equation)
Now,
So, Ep = 0.67 → Demand is inelastic at that point.
Advantages:
• Very precise, especially when using demand functions.
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• Shows how elasticity changes at different points on the curve.
Limitations:
• Requires knowledge of calculus.
• Not suitable when we only have two price and quantity points.
Summary Table
Method
Usefulness
Accuracy
Ideal For
Total Expenditure
Method
Simple, compares spending
Low
Beginners, quick
judgment
Percentage Method
Calculates exact elasticity value
Medium
General economic
analysis
Point Elasticity
Method
Very accurate using functions
or graphs
High
Advanced analysis &
theory
Final Thoughts
Understanding price elasticity of demand is like understanding customer behavior in real
life. Imagine you’re buying mangoes. If the price increases and you stop buying them, you
are showing elastic demand. If you keep buying even if the price rises (like for salt or
medicine), your demand is inelastic.
The methods above give economists, businesses, and governments the tools to measure
how sensitive people are to price changes, which is extremely useful in setting prices,
predicting sales, or designing policies like taxation.
2. (a) Define equilibrium of consumer through cardinal utility analysis,
Ans: Equilibrium of Consumer through Cardinal Utility Analysis
Introduction
Imagine a person named Rahul who goes to a market with ₹100 in his pocket. He wants to
buy goods that will give him the most satisfaction or utility from that ₹100. But how will he
decide what to buy, how much to buy, and in what combination?
This decision-making process is what we study in consumer equilibrium — a condition
where a consumer maximizes satisfaction given his income and the prices of goods.
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To understand this clearly, economists have developed different theories. One such theory
is the Cardinal Utility Analysis.
What is Cardinal Utility?
The word “Cardinal” means something that can be measured in numbers. So, Cardinal Utility
Analysis assumes that utility or satisfaction can be measured in numbers, just like weight or
height.
For example:
• 1 apple gives Rahul 10 utils of satisfaction.
• 1 banana gives 8 utils of satisfaction.
So, cardinal utility is all about measuring how much satisfaction a consumer gets by
consuming one more unit of a good.
Assumptions of Cardinal Utility Analysis
Before understanding how equilibrium is reached, we must know the assumptions of this
theory:
1. Utility is measurable in cardinal numbers (like 10 utils, 15 utils, etc.).
2. Marginal utility of money is constant, meaning each rupee spent gives equal utility.
3. The consumer has a fixed income.
4. Prices of goods are known and constant.
5. Consumer aims to maximize total satisfaction.
6. The Law of Diminishing Marginal Utility holds true.
Law of Diminishing Marginal Utility
This is a key concept. It says that as a consumer consumes more and more units of a good,
the extra satisfaction (marginal utility) keeps decreasing.
Example:
• 1st apple: 10 utils
• 2nd apple: 8 utils
• 3rd apple: 6 utils
• 4th apple: 3 utils
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So, Rahul will not get the same joy from every apple. His excitement keeps reducing.
What is Consumer’s Equilibrium?
Consumer’s equilibrium means that point where the consumer spends his money in such a
way that he gets maximum satisfaction and has no desire to change how he spends.
Rahul will be in equilibrium when:
Where:
• MUx = Marginal Utility of Good X (e.g., apples)
• Px = Price of Good X
• MUy = Marginal Utility of Good Y (e.g., bananas)
• Py = Price of Good Y
• MUm = Marginal Utility of Money
This condition means:
The utility from the last rupee spent on each good should be equal.
Example to Understand Equilibrium
Suppose:
• Price of 1 apple = ₹5
• Price of 1 banana = ₹2
• Rahul has ₹20
• Marginal utility from apples and bananas is as follows:
Units
MU of Apples
MU of Bananas
1
15
12
2
12
10
3
9
8
4
6
6
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Units
MU of Apples
MU of Bananas
5
3
4
Now, let's calculate MU per ₹ (Marginal Utility per Rupee):
For Apples:
• 1st: 15 / 5 = 3
• 2nd: 12 / 5 = 2.4
• 3rd: 9 / 5 = 1.8
• 4th: 6 / 5 = 1.2
• 5th: 3 / 5 = 0.6
For Bananas:
• 1st: 12 / 2 = 6
• 2nd: 10 / 2 = 5
• 3rd: 8 / 2 = 4
• 4th: 6 / 2 = 3
• 5th: 4 / 2 = 2
Rahul will choose the goods with the highest MU per ₹ until he exhausts ₹20. He will go
step by step:
1. Buy 1st banana (MU/₹ = 6) → ₹2
2. Buy 2nd banana (MU/₹ = 5) → ₹2 (Total = ₹4)
3. Buy 3rd banana (MU/₹ = 4) → ₹2 (Total = ₹6)
4. Buy 1st apple (MU/₹ = 3) → ₹5 (Total = ₹11)
5. Buy 4th banana (MU/₹ = 3) → ₹2 (Total = ₹13)
6. Buy 2nd apple (MU/₹ = 2.4) → ₹5 (Total = ₹18)
7. Buy 5th banana (MU/₹ = 2) → ₹2 (Total = ₹20)
Now he has spent ₹20, and the MU/₹ of the last apple and banana is nearly equal (2.4 and
2). This is his equilibrium.
Diagram of Consumer’s Equilibrium (Single Commodity Case)
If the consumer is buying only one good, then equilibrium is when:
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MUx = Px
Diagram:
Summary
• Consumer equilibrium is the point where the consumer gets maximum satisfaction
from their income.
• In Cardinal Utility Analysis, we measure utility in numbers.
• The consumer reaches equilibrium when:
• The Law of Diminishing Marginal Utility plays a crucial role.
• At equilibrium, the last rupee spent on each good gives equal utility.
(b) Critically examine revealed preference hypothesis.
Ans: Introduction
Imagine you go to a market and buy a basket of goods—say 2 bananas and 1 apple. Out of
all the fruits available, you chose this combination. Now, someone might wonder: Why did
you pick this basket and not something else? This is where the Revealed Preference
Hypothesis (RPH) comes in. It helps economists understand your choices not based on what
you say, but based on what you actually do.
The Revealed Preference Hypothesis was introduced by economist Paul Samuelson in 1938.
Instead of assuming what consumers prefer, Samuelson said: Let’s observe what they buy.
Their actions will reveal their preferences.
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What is Revealed Preference Hypothesis?
Definition:
The Revealed Preference Hypothesis suggests that a consumer's preference for goods can
be understood by their actual choices or behavior rather than their stated desires.
If a consumer chooses bundle A over bundle B when both are affordable, then we say that
the consumer "reveals" a preference for A over B.
Assumptions of Revealed Preference Hypothesis
To understand and apply the RPH, Samuelson made some important assumptions:
1. Rationality: Consumers are rational. This means they always try to get the most
satisfaction from their money.
2. Consistency: If a person prefers A over B once, they will always prefer A over B in
similar situations.
3. Transitivity: If a person prefers A over B and B over C, then they will prefer A over C.
4. Fixed income and prices: Consumer’s income and market prices are constant during
the choice.
5. Only observed choices matter: We don’t consider what people say, only what they
buy.
Illustration with Diagram
Let’s take a simple example.
Suppose a consumer has ₹100 to spend.
• Price of Apple = ₹10
• Price of Banana = ₹20
This gives the consumer several combinations of apples and bananas.
Let’s draw a budget line:
Budget Line Diagram:
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Suppose the consumer chooses a bundle of 3 apples and 2 bananas.
Now, this reveals the consumer prefers this combination over all other affordable
combinations.
Types of Revealed Preference Axioms
To make this idea more rigorous, economists introduced axioms (rules):
1. Weak Axiom of Revealed Preference (WARP)
If A is revealed preferred to B, then B cannot be revealed preferred to A.
Example:
If you choose bundle A over B when both are affordable, you should not choose B over A in
another situation where A is still affordable. Otherwise, it becomes inconsistent behavior.
2. Strong Axiom of Revealed Preference (SARP)
If A is preferred to B, and B is preferred to C, then A must be preferred to C.
This follows transitivity and ensures that preferences are not only consistent but also logical
over multiple choices.
Merits of Revealed Preference Hypothesis
1. Based on real behavior – It doesn't rely on unrealistic assumptions like "utility"
or "indifference curves".
2. Scientific and objective – It uses actual data and avoids guesswork.
3. Avoids psychological assumptions – We don’t need to know how people think,
just how they act.
4. Applicable in market research – Helps businesses understand what consumers
actually prefer.
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Criticisms of Revealed Preference Hypothesis
Despite its merits, RPH has some serious limitations:
1. Ignores preference intensity
RPH tells us what is preferred, not how much it is preferred. It cannot say, for example, that
A is strongly preferred over B.
2. Does not handle choices involving same bundles
If someone buys the same bundle repeatedly, we cannot make new inferences about their
preferences.
3. No room for change in taste
It assumes tastes are stable and consistent, but in real life, people change their preferences
over time.
4. Problem with corner solutions
Sometimes people buy only one good and none of the others (corner solution). In this case,
we cannot say whether they preferred it or were simply limited by price or availability.
5. Cannot handle risk or uncertainty
RPH works under the assumption that choices are made with full knowledge. But in real life,
people face risk and uncertainty.
Conclusion
The Revealed Preference Hypothesis is a powerful tool in economics. It brought a major shift
from the traditional idea of "imagined preferences" to "observed behavior". Paul
Samuelson's idea made economics more scientific by linking theory to data.
However, it has its limitations. It assumes that people are always rational and consistent,
which might not be true in every case. Despite these limitations, RPH still serves as a useful
foundation for consumer behavior analysis, market studies, and policy-making.
SECTION-B
3. State and explain the law of variable proportions. In which stage of law does a typical
business firm operate?
Ans: Introduction
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Imagine a small bakery. The owner, Ramu, has a fixed-size oven and kitchen (fixed factors),
but he can hire more workers and buy more flour and sugar (variable factors). At first, when
he hires 1 or 2 helpers, production increases significantly. But after a point, hiring more
workers leads to smaller increases in production. Eventually, if he keeps hiring, the kitchen
gets crowded, people get in each other’s way, and production might even decrease.
This everyday example introduces us to an important concept in economics — The Law of
Variable Proportions.
Meaning of the Law
The Law of Variable Proportions is a fundamental concept in production theory in
microeconomics. It explains how output changes when the quantity of one input (like labor)
is increased, while keeping other inputs (like capital or land) fixed.
This law is also called the Law of Diminishing Returns or Law of Diminishing Marginal
Product.
Definition
According to the law:
“As we increase the quantity of one input, keeping all other inputs fixed, the total output
initially increases at an increasing rate, then at a diminishing rate, and eventually
decreases.”
This law applies in the short run, where at least one input is fixed (usually capital like
machines, land, etc.).
Assumptions of the Law
1. One input is variable (e.g., labor) while others are fixed (e.g., land, machines).
2. Technology remains constant.
3. Inputs are homogeneous (each unit of labor is equally efficient).
4. The production process is divisible (inputs can be added in small amounts).
Key Concepts
To understand this better, let's look at three terms:
1. Total Product (TP): The total output produced by all units of the variable input.
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2. Marginal Product (MP): The extra output from adding one more unit of the variable
input.
MP = Change in TP / Change in input
3. Average Product (AP): Output per unit of the variable input.
AP = TP / Number of variable inputs
Three Stages of the Law
The behavior of TP, MP, and AP gives rise to three stages of production:
Stage I: Increasing Returns
• TP increases at an increasing rate.
• MP and AP both increase.
• This happens because the fixed input is underutilized, and more workers help use it
better (e.g., one oven can now bake more cakes with more bakers).
• MP is rising.
Graphically: TP curve is convex (rising steeply), MP and AP curves slope upward.
Why increasing returns?
• Better utilization of fixed factors
• Division of labor
• Specialization
Stage II: Diminishing Returns
• TP increases at a decreasing rate.
• MP starts to fall, but is still positive.
• AP also starts to fall, but is still higher than MP for a while.
• The fixed factor becomes a limiting factor (e.g., too many workers sharing one oven).
Graphically: TP curve is concave, MP and AP are declining.
Why diminishing returns?
• Fixed input becomes overutilized
• Coordination problems
• Crowding
This is the most rational stage for a firm to operate.
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Stage III: Negative Returns
• TP starts declining.
• MP becomes negative.
• AP continues to fall.
Graphically: TP curve slopes downward, MP is below zero.
Why negative returns?
• Severe overcrowding
• Output falls due to inefficiency
• Workers hinder each other
Diagram for the Law of Variable Proportions
Here is a basic diagram representing the three stages:
Numerical Example
Units of Labor
Total Product (TP)
Marginal Product (MP)
Average Product (AP)
1
10
10
10
2
25
15
12.5
3
45
20
15
4
60
15
15
5
70
10
14
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Units of Labor
Total Product (TP)
Marginal Product (MP)
Average Product (AP)
6
75
5
12.5
7
70
-5
10
From this table:
• MP rises till 3rd unit → Stage I
• MP falls but stays positive till 6th unit → Stage II
• MP becomes negative after 6th unit → Stage III
In Which Stage Does a Firm Operate?
A typical business firm operates in Stage II. Why?
• In Stage I, the firm is not using its fixed resources fully. It can increase production
more efficiently, so no rational firm will stop there.
• In Stage III, production decreases even as costs rise. No firm would want to produce
less by using more input.
• So, Stage II is ideal because:
o TP is increasing
o MP is positive (but falling)
o The firm can get the most efficient use of resources.
Conclusion
The Law of Variable Proportions shows us how production behaves when more of a variable
input is added to fixed inputs. It reflects a real-world phenomenon—like how too many
cooks in a small kitchen may ruin the broth!
It helps businesses understand the optimum level of input usage, guiding them to operate
efficiently in Stage II, where costs are controlled, and output is maximized.
Understanding this law is essential for economics students, as it lays the foundation for
topics like cost theory, production planning, and resource allocation in the short run.
4. What is meant by total revenue, average revenue and marginal revenue? Discuss the
relationship between AR, MR and Price elasticity of demand.
Ans: 4. Total Revenue, Average Revenue, and Marginal Revenue
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Introduction
Revenue is one of the most important concepts in economics and business. It helps a firm
understand how much money it is earning by selling its goods or services. Just like when a
shopkeeper keeps track of how much he is selling and what he earns per sale, firms too
measure their earnings through Total Revenue (TR), Average Revenue (AR), and Marginal
Revenue (MR). Understanding these concepts helps firms make smart decisions about
pricing and production.
Let’s break these concepts down step by step like a simple story.
Total Revenue (TR)
Total Revenue is the total amount of money a firm receives by selling its products.
Formula:
Example:
If a company sells 10 pens at ₹20 each,
TR increases as the company sells more, but not always at the same rate (as we’ll see later).
Average Revenue (AR)
Average Revenue is the revenue earned per unit of the product sold. It is calculated by
dividing the total revenue by the number of units sold.
Formula:
But here’s the important thing:
In most cases, AR = Price (because TR = P × Q and AR = TR/Q = P).
Example:
If the firm earns ₹200 by selling 10 pens,
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Marginal Revenue (MR)
Marginal Revenue is the additional revenue a firm earns when it sells one more unit of the
product.
Formula:
In simple words, it shows the change in TR when quantity sold increases by one unit.
Example:
Suppose selling 10 pens earns ₹200 and selling 11 pens earns ₹215,
MR=215−200=₹15
So, the extra revenue from selling one more pen is ₹15.
Relationship between TR, AR, and MR
Let’s understand this through a small table and diagram.
Table:
Quantity (Q)
Price (P)
TR = P × Q
AR = TR/Q
MR = ΔTR/ΔQ
1
20
20
20
-
2
19
38
19
18
3
18
54
18
16
4
17
68
17
14
As price falls, TR increases at a decreasing rate, and MR falls.
AR is the same as price in each case.
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Diagram: TR, AR and MR Curves
• The TR curve first rises, reaches a maximum, and then may fall.
• AR and MR curves slope downward in imperfect competition.
• MR falls faster than AR.
Relationship between AR, MR, and Price Elasticity of Demand (Ed)
Now let’s connect revenue with price elasticity of demand, which means how sensitive
buyers are to changes in price.
Formula connecting MR and Ed:
Where:
• MR = Marginal Revenue
• AR = Average Revenue (i.e., Price)
• Ed = Price Elasticity of Demand
Key Interpretations:
If Ed > 1 (Elastic demand):
• Consumers are very responsive to price.
• MR is positive, and lowering price increases TR.
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• Example: Luxury goods, branded clothes.
If Ed = 1 (Unitary elastic):
• MR = 0
• TR is maximum.
• Any change in price doesn’t affect TR.
If Ed < 1 (Inelastic demand):
• Consumers are not responsive to price.
• MR is negative, and lowering price reduces TR.
• Example: Salt, petrol.
Summary Table:
Elasticity (Ed)
TR Behavior
MR
Ed > 1
TR increases
MR > 0
Ed = 1
TR is maximum
MR = 0
Ed < 1
TR decreases
MR < 0
Conclusion:
Understanding TR, AR, and MR helps businesses know:
• How much they are earning,
• How revenue changes when they increase output, and
• Whether changing price is a good idea or not.
By linking these to price elasticity, firms can decide:
• Whether to increase or decrease prices,
• Where their maximum revenue lies, and
• How consumers might react.
It’s like driving a car: Price is the steering wheel, Elasticity is the road condition, and
Revenue is the journey. Smart drivers (businesses) always keep their eyes on all three!
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SECTION-C
(5). What are the characteristics of perfect competition? How is equilibrium of a firm
determined under perfect competition in the short period and long period ?
Ans: What are the Characteristics of Perfect Competition?
Imagine a large vegetable market where hundreds of farmers are selling identical tomatoes.
All sellers are shouting prices, but they all charge the same amount, and buyers can buy
from anyone without worrying about the quality or price. This is a simple way to imagine
perfect competition.
Perfect competition is a theoretical market structure in economics that helps us understand
how prices and outputs are determined in the most efficient way.
Main Characteristics of Perfect Competition
1. Large Number of Buyers and Sellers
o In perfect competition, there are many buyers and sellers, so no single buyer
or seller can influence the market price.
o Everyone is a price taker, not a price maker.
2. Homogeneous Product
o All firms sell an identical product. For example, one kilogram of wheat from
one farmer is exactly the same as from another.
3. Free Entry and Exit
o Firms can enter or leave the market freely without any legal or financial
barriers.
4. Perfect Knowledge
o All buyers and sellers have full information about prices, product quality, and
availability.
5. Perfect Mobility of Factors
o Resources like labor and capital can move freely from one use to another or
from one firm to another.
6. No Government Intervention
o There are no taxes, subsidies, price controls, or restrictions affecting the
market.
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Equilibrium of a Firm under Perfect Competition
Let’s now understand how a firm reaches equilibrium (a point of balance) under perfect
competition.
A firm is in equilibrium when it has no tendency to increase or decrease output, i.e., when it
is maximizing its profit.
We will discuss this in two parts:
A. Short-Run Equilibrium of a Firm
The short run is a period in which some factors (like capital, land) are fixed, and only labor or
raw materials can be changed.
Assumptions in the Short Run
• The firm cannot change plant size or machinery.
• The number of firms is fixed.
• Price is determined by the market.
Conditions for Equilibrium
In the short run, a firm reaches equilibrium where:
Marginal Cost (MC) = Marginal Revenue (MR)
And, MC curve cuts MR from below
Since the firm is a price taker, the price (P) = MR = AR (Average Revenue)
Short-Run Diagram
Equilibrium Output: Where MC = MR
Profit or Loss: If AR > AC → Profit; if AR < AC → Loss
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Three Possibilities in the Short Run
1. Supernormal Profit (AR > AC)
2. Normal Profit (AR = AC)
3. Loss (AR < AC) – But firm may still operate if it covers average variable cost
B. Long-Run Equilibrium of a Firm
The long run is a period when all factors are variable. Firms can change plant size and new
firms can enter or leave the market.
Assumptions in the Long Run
• No fixed inputs; all inputs can be changed.
• Firms can enter or exit freely.
• All firms have identical cost structures.
Condition for Long-Run Equilibrium
Price = Marginal Cost = Average Cost
i.e., P = MC = AC
Firms earn normal profit in the long run. If they were making more, new firms would enter
and increase supply, reducing prices. If they were making losses, some would exit,
decreasing supply and raising prices.
Long-Run Diagram
The firm produces at the minimum point of AC curve.
It earns zero economic profit, which means normal profit only.
Conclusion: A Story Summary
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Think of a firm like a tea seller in a long street full of tea sellers (perfect competition).
• In the short run, he might make extra profit or face losses because others can’t
quickly open new stalls or shut down.
• But in the long run, if he makes profit, new sellers come and reduce his price. If he
makes loss, some leave, and price increases.
• Eventually, he earns just enough to stay in the business – no more, no less.
This is how perfect competition works—it ensures efficiency, keeps prices low for
consumers, and encourages innovation and productivity in the long term.
6. What is meant by monopolistic competition? How is equilibrium of firm and group
determined under monopolistic competition?
Ans: Monopolistic Competition – A Real-World Market Story
Imagine you're walking down a busy street full of small restaurants. Each restaurant sells
food – say, pizza – but every place has something different: one has cheese burst, one has a
wood-fired oven, one adds exotic herbs, and another has cozy candlelight seating. All sell
pizza, but no two are exactly the same. This is the perfect example of monopolistic
competition.
What is Monopolistic Competition?
Monopolistic competition is a type of market structure where many sellers offer similar but
not identical products. Each firm tries to create a unique identity through branding, quality,
features, services, or location. This results in product differentiation.
Key Features of Monopolistic Competition:
1. Many Sellers – There are a large number of firms, but each has a small market share.
2. Product Differentiation – Every firm offers slightly different products.
3. Free Entry and Exit – New firms can enter or exit the market freely.
4. Selling Costs – Firms use advertisement and promotions to attract customers.
5. Independent Decision Making – Each firm makes its own pricing and output
decisions.
Equilibrium of a Firm under Monopolistic Competition
Let's now understand how an individual firm (say, your pizza shop) sets its price and output
in such a market.
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Short-Run Equilibrium of the Firm
In the short run, firms can make supernormal profits, normal profits, or even losses,
depending on demand and cost conditions.
Diagram: Short-Run Equilibrium
We can use a basic economic diagram with AR (Average Revenue), MR (Marginal Revenue),
AC (Average Cost), and MC (Marginal Cost) curves.
• The firm is in equilibrium where MR = MC (profit-maximizing condition).
• If AR > AC at that output level, the firm earns supernormal profits.
• If AR = AC, the firm earns normal profit.
• If AR < AC, the firm incurs losses, but it may continue in the short run if it covers
variable costs.
Long-Run Equilibrium of the Firm
Now think long term. If your pizza shop is doing well and making profits, more people will
open similar shops nearby. Due to free entry, new firms will enter the market. This increases
competition and reduces the market share of each existing firm.
As a result:
• The AR curve shifts leftward (demand decreases).
• Supernormal profits disappear.
• Each firm adjusts its output where MR = MC, and now AR = AC.
• Firms earn only normal profits in the long run.
Diagram: Long-Run Equilibrium
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Here, the firm produces at the point where it just covers its costs, no profits or losses, and
still maintains product differentiation.
Equilibrium of the Group under Monopolistic Competition
The “group” means all the firms in the monopolistic competition market that produce close
substitutes. Their combined behavior forms the group equilibrium.
Characteristics of Group Equilibrium:
• All firms make normal profits in the long run.
• No firm has incentive to enter or exit.
• There is excess capacity (firms don’t produce at the lowest point of AC curve).
• Product differentiation continues, and firms compete through non-price competition
like branding, service, etc.
Excess Capacity Explained:
In perfect competition, firms produce at the lowest point of the AC curve, which is
considered efficient.
In monopolistic competition:
• Firms produce at a lower level of output than that.
• This leads to excess capacity.
• It means resources are underutilized, and production is not at its optimal level.
Why Firms Don’t Reduce Prices to Increase Sales?
You may wonder, "Why doesn’t a firm just reduce its prices to increase customers?" The
reason is:
• Lower prices may not attract loyal customers who prefer differentiated features.
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• It might reduce profit margins.
• Other firms might also reduce prices, leading to a price war.
So, firms often compete in other ways, such as:
• Better customer service.
• Advertising.
• Product variety.
Conclusion
Monopolistic competition is a mix of monopoly and perfect competition. Firms have some
power to set prices due to product differentiation but also face competition due to many
close substitutes. In the short run, they can earn profits or losses, but in the long run, only
normal profits are possible due to new entries and exits.
This market structure is the most common in the real world – like cafes, salons, clothing
brands, and small electronics – where variety, branding, and marketing play as big a role as
price.
SECTION-D
7. Critically examine the neo-classical marginal productivity theory of distribution.
Ans: Introduction
Imagine a bakery that produces cakes. To produce those cakes, the bakery uses inputs like
flour (capital), bakers (labour), machines (tools), and land (space). Now the big question is:
How should the income generated from selling these cakes be divided among all these
inputs? Should the baker get more? Or the machine owner?
This is where the Neo-Classical Marginal Productivity Theory of Distribution comes in. It tries
to answer how the total income (or output) of a firm or the economy should be distributed
among the different factors of production — Land, Labour, Capital, and Entrepreneurship.
What Is the Marginal Productivity Theory?
The Marginal Productivity Theory says:
"Every factor of production is paid according to its marginal productivity — the extra output
it adds when one more unit of it is employed, keeping all other factors constant."
In short:
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• Labour is paid according to its marginal productivity (MPL).
• Capital is paid according to its marginal productivity (MPK).
• And so on...
Basic Concepts to Understand First
1. Marginal Product (MP)
This is the additional output produced by using one extra unit of a factor, while keeping all
others constant.
Example: If adding one more worker increases production from 50 to 60 cakes, then MP
= 10 cakes.
2. Marginal Revenue Product (MRP)
This is the money value of the marginal product. It is calculated as:
Where MR = Marginal Revenue.
If one more worker produces 10 more cakes, and each cake sells for ₹10, then MRP = 10 ×
10 = ₹100.
3. Equilibrium Condition
In a perfectly competitive market, the firm will hire a factor (like labour) until:
This applies to all factors:
Diagram to Explain
Marginal Revenue Product Curve
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The MRP curve slopes downward, showing that as more units of labour are used, each
additional worker contributes less (law of diminishing returns).
Assumptions of the Theory
1. Perfect competition in factor and product markets.
2. Homogeneous factors (all workers are equally skilled, etc.).
3. Diminishing marginal returns.
4. Full employment of resources.
5. Factors are divisible and mobile.
6. Profit maximization by firms.
Critical Examination of the Theory
Strengths of the Theory
1. Logical and Simple
It provides a clear and logical explanation of how factor prices are determined.
2. Based on Productivity
It encourages efficiency — the more productive you are, the more you earn.
3. Useful for Policy
It helps in wage determination, especially in competitive industries.
Criticisms of the Theory
1. Unrealistic Assumptions
o Perfect competition doesn’t exist in the real world.
o Workers are not all the same (they have different skills and experiences).
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2. Measurement Difficulties
o It’s very hard to measure marginal productivity of factors like labour and
capital in real life.
3. Ignores Collective Bargaining
o Wages are not always based on productivity but on unions, laws, and
negotiations.
4. Overlooks Human Factors
o Workers are treated like machines. But humans have emotions, needs, and
social backgrounds.
5. Does Not Explain Distribution of Property
o It does not explain why some people own more capital or land in the first
place.
6. Static Theory
o It ignores technological progress and dynamic economic conditions.
Modern View and Modifications
Modern economists accept the basic idea of marginal productivity but relax some
assumptions:
• Acknowledge imperfect competition.
• Recognize the role of government, unions, and institutions.
• Accept that real-world factors like education, training, and discrimination also
influence factor prices.
Conclusion
To conclude, the Neo-Classical Marginal Productivity Theory of Distribution is a foundational
theory in economics. It provides a clean and mathematical way to understand how wages,
rents, interest, and profits are determined.
But in the real world, the theory is too idealistic. It fails to account for the imperfections,
inequalities, and human complexities in markets.
Still, it remains important as a starting point and has influenced many modern economic
models and policies. To make it more practical, it must be combined with real-world
insights.
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8. (a) 'Rent is surplus of actual earning over transfer earnings. Discuss.
Ans: “Rent is surplus of actual earning over transfer earnings” – Explained Simply
In economics, we often hear the word “rent”, and most people think of paying money to live
in a house. But in economics, “economic rent” is quite different. It refers to a surplus —
something extra — earned by a factor of production (like land, labor, or capital) over and
above what is necessary to keep it in its current use. Let’s understand this in a simple and
story-like manner.
The Two Earnings: Actual vs Transfer
Actual Earnings:
This is the real income or payment that a factor of production receives.
For example, if a piece of land is used for farming and earns ₹10,000 per month, then
₹10,000 is its actual earning.
Transfer Earnings:
This is the minimum payment required to keep that factor in its current use.
Suppose the land could also be used for growing flowers and would earn ₹6,000 per month
in that use, then ₹6,000 is the transfer earning.
Economic Rent = Actual Earning – Transfer Earning
Using our example:
₹10,000 (actual) – ₹6,000 (transfer) = ₹4,000
This ₹4,000 is the economic rent.
It is a surplus — not needed to keep the land in its present use, but earned anyway.
Explaining with a Real-Life Example
Let’s say Rohan owns a piece of land in Punjab. He has two options:
1. Rent it out to a wheat farmer and get ₹20,000/month.
2. Rent it out to a flower grower and get ₹15,000/month.
He chooses the wheat farmer. So:
• Actual earning = ₹20,000
• Transfer earning = ₹15,000
• Rent (economic rent) = ₹5,000
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This ₹5,000 is the extra income over what Rohan would have accepted to keep the land in
use. It's a surplus, or economic rent.
Key Concepts Explained
1. Economic Rent Is Not Always About Land
Although the term originated with land, any factor of production (like labor, machines, etc.)
can earn economic rent.
Example with Labor:
Imagine a famous actor is paid ₹10 crore for a film. He would have been happy with ₹3 crore
(his transfer earning), so ₹7 crore is his economic rent — surplus over what is necessary to
keep him acting in the movie.
2. No Rent When Transfer Earnings = Actual Earnings
If Rohan’s land earns ₹15,000 in both wheat and flower farming, then:
• Actual earning = ₹15,000
• Transfer earning = ₹15,000
• Economic rent = ₹0
In this case, there’s no surplus, so no rent.
3. Scarcity Creates Rent
Economic rent exists when a resource is scarce or unique — for example, fertile land, rare
talent, or prime city locations.
Diagram to Illustrate Economic Rent
Let’s look at a simple diagram:
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• The upper block is the economic rent.
• The lower block is the minimum required payment (transfer earning).
Importance of Economic Rent in Economics
Helps in Resource Allocation:
Economic rent shows where resources are most valuable. High rent = high value.
Government Taxation:
Governments can tax economic rent without affecting production, because it is surplus and
not necessary to keep resources in use.
Wage Differences:
Some workers earn economic rent due to skill or popularity — such as celebrities, top
athletes, etc.
Conclusion:
Economic rent is not rent in the everyday sense of the word. It is a surplus — an earning
over and above what is necessary to keep a resource in its current use. When actual
earnings are greater than transfer earnings, the extra part is economic rent. This concept
helps us understand how resources earn extra income, how inequalities may arise, and how
governments might tax certain types of income.
So next time you hear "rent" in economics, remember: it's not about houses — it’s about
surplus earnings that arise from scarcity, uniqueness, or specialized ability.
(b) Explain Knight's uncertainty theory of profit. What objections are raised against it?
Ans: Introduction
In economics, the concept of profit is more than just revenue minus costs. One of the most
interesting and important theories about the origin of profit was given by Frank H. Knight, a
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well-known American economist. His Uncertainty Theory of Profit adds a new and practical
dimension to understanding how profit arises in real-world business situations.
Let’s understand this theory like a story.
The Main Idea – What is Knight Saying?
According to Knight, profit is the reward for bearing uncertainty.
He made a very important distinction between two terms:
1. Risk
2. Uncertainty
Although we usually think of both as the same, Knight said they are different – and
understanding this difference is the key to understanding why businesses earn profit.
Risk vs Uncertainty: What's the Difference?
Aspect
Risk
Uncertainty
Definition
Situations where outcomes are
unknown, but probabilities can be
calculated.
Situations where outcomes are
unknown and probabilities cannot be
calculated.
Example
Tossing a coin (50% chance of head
or tail)
Launching a new product in a new
market with unknown customer
response.
Measurable?
Yes (using statistics or probability)
No (not measurable in advance)
Insurable?
Yes
No
According to Knight, risk can be insured, but uncertainty cannot.
This means when a business person makes a decision in an uncertain environment (like
introducing a new innovation or entering a new market), he cannot predict the outcome or
insure against the loss. If he succeeds, the reward he earns is called profit.
Real-World Example:
Let’s say you start a startup to sell smart shoes that track health. No one has tried this
before in your area. You don’t know:
• If customers will like them.
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• If production cost will stay under control.
• If competitors will enter soon.
You're not dealing with calculable risks but uncertainties.
If your product becomes a hit, and you make money, that profit is your reward for taking
the uncertain decision.
Diagrammatic Representation:
Here’s a simplified visual to help:
Key Features of Knight’s Theory:
1. Profit is not due to routine operations – Running a business normally with no
uncertainty doesn’t give profit, only wages or returns.
2. Only those who take uncertain decisions get profit – Like entrepreneurs, inventors,
or risk-takers.
3. Profit is temporary – Once the uncertainty becomes known (for example, others
copy your idea), profit disappears.
4. Uncertainty is the real source of profit – not land, labour, or capital.
Objections to Knight’s Theory:
Though Knight’s theory is valuable, economists and scholars have raised some objections:
1. Profit is also earned in riskless situations:
o Some businesses earn regular profits even when there is no uncertainty.
Example: Utilities or monopolies.
2. Neglects other sources of profit:
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o It ignores factors like innovation (as Schumpeter said), market power,
monopoly, and technological advantage.
3. Too theoretical:
o It is more of a philosophical explanation than a practical one. It’s hard to
measure "uncertainty" exactly.
4. Does not explain how much profit:
o The theory tells us the reason for profit but not how much profit will be
earned.
5. Ignores coordination and management skills:
o A good manager who ensures smooth coordination of all activities also earns
profit. Knight’s theory does not highlight this.
Conclusion:
Knight’s Uncertainty Theory of Profit provides a deep and thoughtful insight into how
businesses actually operate in the real world. It tells us that true profit is a reward for
courage — the courage to take uncertain decisions in unknown situations.
While the theory is not perfect and has limitations, it emphasizes the entrepreneurial spirit
that drives innovation and progress in any economy.
“This paper has been carefully prepared for educational purposes. If you notice any mistakes or
have suggestions, feel free to share your feedback.”
