A perfect market is characterised by perfect competition. The conditions that result in perfect competition include:

  • Equal access to the technology required for production
  • No barriers to entry or exit from the marketplace
  • Accurate and available market information
  • No participant with the power to set the market price
  • According to equilibrium theory, a perfect market will reach an equilibrium where the quantity supplied equals the quantity demanded at the market price

Overview

MAIN TOPIC: MICROECONOMICS   
 TOPIC CONTENT  CONTENT DETAILS FOR TEACHING,
LEARNING AND ASSESSMENT PURPOSES 
6. Dynamics
of markets:
Perfect
markets 

Examine the dynamics of perfect markets with
the aid of cost and revenue curves

  1. Review cost and revenue tables and
    curves done in Grade 11.
  2. Differentiate between the short and
    long run.
  • Perfect competition
    • Description
    • Characteristics/conditions
  • Individual business and industry
    • The demand curve for:
      • Individual business
      • The industry
    • Profit maximization
    • Derivation of supply curve from cost curves
  • Market structure
    • Definition
    • Characteristics
      • Number of businesses
      • Nature of product
      • Entrance
      • Control over prices
      • Information
      • Examples
      • Demand curve
      • Economic profit
      • Collusion
      • Allocative efficiency
      • Technical efficiency
  • Output, Profits, Losses and Supply
    • Individual business
      • Short run (economic profit, economic loss,
        normal profit)
      • Long run (normal profit)
      • Shut-down/closing down
    • The industry
      • Short-run (economic profit, economic loss,
        normal profit)
      • Long run (normal profit)
  • Competition policies
    • Description
    • Goals with the competition policy
    • Anti-monopoly policy
      • Competition Policy, Act 89 of 1998
      • Competition Commission
      • Competition Tribunal
      • Competition Appeal Court

HOT QUESTION: Examine in detail how
cost and revenue curves can be used
to illustrate and explain the dynamics
(working) of markets

  • Explain the concept
  • Examine the characteristics of a
    perfect market in detail
  • Compare the individual businesses to
    the industry in detail
  • The examination of individual business
    and industry should be accompanied
    by an analysis of tables and graphs

HOT QUESTION: Explain why the
individual maize, wheat or milk farmer
does not have an influence on the price
of their products in the market

  • Define the concept
  • Compare and contrast the FOUR broad
    types of market structures

As the various market structures
are discussed in detail, all
characteristics will feature.

  • Examine in detail the THREE
    equilibrium positions with the aid of
    graphs
  • Explain shut-down/closing down point
    with the aid of a graph

When teaching the various
equilibrium positions a link must
be made between individual
businesses and the industry.

HOT QUESTION: Draw three fully labelled
graphs showing the possible equilibrium
positions of a business operating under
perfect market conditions

  • Define/explain the policy
  • Briefly discuss/analyse the goals of the
    SA competition policy
  • Briefly analyse the SA Anti-monopoly
    policy
  • Briefly discuss the Competition policy
    Act and its implications highlighting the
    roles of the key institutions
  • Give your opinion about the successes/
    failures of the Competition policy Act

HOT QUESTION: In your opinion is the
competition policy in South Africa
destroying or saving businesses?

6.1 Key concepts

These definitions will help you understand the meaning of key Economics concepts that are used in this study guide. Understand these concepts well.

Term  Definition 
Economic loss  When total costs are greater than total revenue. When average revenue is lower than average cost the firm makes an economic loss 
Economic profit   Profit that is made in addition to normal profit. When average revenue is greater than average cost the firm makes an economic profit
Explicit cost  Actual expenditure of business, e.g. wages and interest
Implicit cost  Value of inputs owned by entrepreneur and used in the production process (forfeited rental, interest + salary)
Long run   The period of production where all factors can change.
The time is long enough for variable and fixed factors to change
Market   An institution or mechanism that brings together buyers and sellers of goods or services
Market structure  How a market is organised
Monopolistic competition A market structure in which businesses have many competitors, but each one sells a slightly different product (e.g. CD’s and books)
Monopoly Exclusive control of a commodity or service in a particular market
Normal profit The minimum earnings required to prevent an entrepreneur from leaving the industry. When average revenue equals average cost the firm makes a normal profit
Oligopoly A market structure controlled by a small group of businesses
Perfect competition A market structure with large numbers of producers and buyers
Price taker Has no influence on price. Takes price that is determined by the market
Short run The period of production where only the variable factors of production can change while at least one factor is fixed
Shut-down point Business will close where MC = AVC
The Competition Appeal Court An institution whose main functions is to review orders made by the Competition Tribunal and amend or confirm these orders
The Competition Commission An institute that investigates restrictive business practices, abuse of dominant positions and mergers in order to achieve equity in the South African economy
The Competition Tribunal An institution whose main function is to approve large mergers, adjudicate in the case of misconduct and issue orders on matters presented to it by the Competition Commission

Use mobile notes to help you learn these concepts. Instructions for making them are on page xiv in the introduction.

6.2 Review of production, costs and revenue

Production takes place in the short run and the long run

  • Short run
    The short run is the period of production where only the variable factors of production can change. The time period is too short to permit the number of firms in the industry to change.
  • Long run
    The long run is the period of production where all factors can change. The time is long enough for variable and fixed factors to change. It allows enough time for new firms to enter the industry and/or existing firms to exit.
Total Product/Output  Total product is the maximum output that the firm can produce with the given number of fixed and variable inputs at its disposal   
Marginal Product/Output   Marginal product is the additional unit of output which is produced as one more unit of the variable input (labour) is combined with the fixed input MP=ΔTP
        ΔQ 
Average Product/Output  Average product of a variable input shows the contribution that each labourer makes towards production AP =
        Q
Fixed Costs (indirect costs/overhead costs)  Costs that remain the same even if the output changes. Examples are rent, depreciation, insurance  
Variable Costs (direct costs/prime costs) Costs that change according to changes in output. E.g. wages the cost of raw materials, electricity etc.  
Total cost   The cost/remuneration for all the factors of production used in the production process  TC = FC + VC 
Marginal costs  Marginal cost is the amount by which total cost increases when one extra product is produced MC = ΔTC
           ΔQ
Average cost Average cost is the cost per unit of production  AC = AFC + AVC or TC
     Q
Average fixed cost To calculate average fixed costs, we divide fixed costs by the amount of goods produced AFC = FC
            Q
Average varible cost To calculate average variable costs, we divide variable costs by the amount of goods produced AVC = VC 
            Q
Total Revenue Total revenue is the total income received from the sale of goods or services TR = P × Q
Marginal revenue Marginal revenue refers to the extra amount of income gained by selling one more unit of production MR = ΔTR
           ΔQ
Average revenue Average revenue refers to the amount a firm earns for every unit sold AR = TR 
          Q

Table 6.1: Review of production, costs and revenue
It is important to review production, cost and revenue concepts covered in Grade
11. This is vitally important for the understanding of cost and revenue curves for the different market structures which you will study in this section.

Summary of costs

Cost schedule for Kael’s Pie shop        
 Q  TFC TVC  TOTAL COSTS AFC = TFC
             Q 
AVC = TVC
             Q
(ATC = AFC + AVC) or TC
                                     Q 
MC = ΔTC
           ΔQ 
 0  120  0 120 - - -  
 10  120  100  220  12  10  22  10
 20  120  160  280  6  8  14  6
 30  120  210  330  4  7  11  5
 40  120  280  400  3  7  10  7
 50  120  400  520  2.4  8  10.4  12
 60  120  600  720  2  10  12  20
 70  120 910 1030 1.7 13  14.7 31

Table 6.2: Summary of costs
The following sketches should resemble the shape for the above cost curves.
6.1
Important observations

  • The difference between the total cost and variable cost is the fixed cost
  • TVC curve starts from 0 and TC starts from the fixed cost curve on the Y- axis.
  • The gap between the AC curve and the AVC curve gets smaller as output increases.
  • The MC Curve will always cut the AC and AVC curves at their minimum points.

6.3 Perfect competition

Perfect competition occurs in a market structure with a large number of participants who have access to all required information about the market place and are all price-takers. Prices are determined by demand and supply. Examples of market structures demonstrating most conditions of a perfect competition include the stock exchange, the foreign exchange market, the central grain exchange, and agricultural produce markets.
A perfect market is a market where no single buyer or seller has a noticeable influence on the price of a good. This gives a true reflection of the scarcity value of goods and services.
6.3.1 Characteristics/conditions of a perfect market
Products must be homogenous (i.e. identical)

  • Products must be identical. There should be no differences in style, design and quality.
  • In this way products compete solely on the basis of price and can be purchased anywhere.

There should be a large number of buyers and sellers

  • It should not be possible for one buyer or seller to influence the price.
  • When there are many sellers the share of each seller in the market is
    so small that the seller cannot influence the price.
  • Sellers are price takers, they accept the prevailing market price. If they increase prices above the market price, they will lose customers.

No preferential treatment/discrimination

  • Collusion occurs when buyers and sellers make an agreement to limit competition. In a perfect market no collusion takes place.
  • Buyers and sellers base their actions solely on price, homogenous products fetch the same price and therefore no preference is shown for buying from or selling to any particular person.

Free competition

  • Buyers must be free to buy whatever they want from any firm and in any quantity.
  • Sellers must be free to sell what, how much and where they wish.
  • There should be no State interference and no price control.
  • Buyers should not form groups to obtain lower prices, nor should sellers combine to enforce higher prices.

Efficient transport and communication

  • Efficient transport ensures that products are made available everywhere.
  • In this way changes in demand and supply in one part of the market will influence the price in the entire market.
  • Efficient communication keeps buyers and sellers informed about market conditions.

All participants must have perfect knowledge of market conditions

  • All buyers and sellers must be fully aware of what is happening in any part of the market.
  • Technology has increased competition as information is easily obtained via the internet.

Free access to and from markets

  • Producers may enter and leave a market with little interference.
  • Entering and leaving a perfect market is easy as less capital is required and there are fewer legal restrictions.

The factors of production are completely mobile

  • They can move freely between markets.

In reality there are few perfect markets, however there are some sectors such as mining (e.g. gold) and agriculture (e.g. maize) where many of the conditions are met. These sectors illustrate the way in which the market mechanism works.

6.4 The individual business and the industry

6.4.1 Determining the market price
To determine the market price for a firm under perfect competition you need to draw two graphs next to each other. On the left is the graph for the industry and on the right is the graph for the firm (individual producer).

  • Figure 6.2 a) (the industry) shows the interaction of demand and supply (market forces).
  • The market forces are in equilibrium at the point of intersection of the demand and supply curves, at “e”.
  • At equilibrium the quantity demanded is equal to the quantity supplied. This determines the market price.
  • Now look at Figure 6.2 b) (firm or individual producer). One producer will not be able to influence the market price and has to accept the market price (P1), he is a price taker.
  • Because this is the only price the producer can charge, the demand curve for the producer is a straight line drawn at price P1.
  • This horizontal line at the market price (P1) is the demand curve (DD), the average revenue (AR) curve and the marginal revenue (MR) curve.

6.2

Read this section on graphs through five times, and redraw each graph each time.
6.4.2 Demand curve for an individual producer
The individual producer is a price taker and sells goods at the market price. At this price, demand remains constant. A higher price such as P2 cannot be charged as customers will be lost to other producers.
A lower price such as P3 cannot be charged as a small profit or a loss will be made.

Quantity  Price (P)  Total Revenue  Marginal Revenue
MR = ΔTR
           ΔQ 
Average Revenue
AR = TR
          Q 
 0   5  0   5   5
 1   5  5   5   5
 2   5  10   5   5
 3   5  15   5   5
 4   5  20   5   5
 5   5  25   5   5
 6   5  30   5   5

Table 6.3: depicting the DEMAND, MARGINAL REVENUE and AVERAGE REVENUE for an individual producer in a perfect market.
Remember that demand = AR = MR = P
6.3
6.4.3 Profit maximisation
Occurs in 2 ways:
1.

Quantity  Price (P)  Marginal Revenue Marginal cost Contribution to profits
 1   5   5   2 3
 2   5   5   3 2
 3   5   5   4 1
 4   5   5   5 0
 5   5   5   6 -1
 6   5   5   7 -2

Table 6.4: Depicting profit maximisation
6.4
Profit maximisation occurs where MR = MC

  • At all pionts where MR is above MC, the firm is adding to profit. From unit 1-3, the firm is increasing its profit.
  • At all points where MC is above MR, the firm is decreasing profit. From unit 5-7, the firm’s profit will decrease.
  • The firm maximises profit where MR = MC. The firm maximises its profits at unit 4.

2.

Quantity  Price (P)  Total Revenue  Total cost Profit (Difference between revenue and cost)
 0   5  0   1   -1
 1   5  5   3   2
 2   5  10   6   4
 3   5  15   10   5
 4   5  20   15   5
 5   5  25   21   4
 6   5  30   28   2

Table 6.5: Depicting Profit Maximisation

  • If TC > TR the business makes a loss. If TR > TC it makes a profit.
  • Maximum profit is achieved at units 3 and 4.
  • Once the maximum profit is achieved, profits start to decrease with the next unit of output.
  • Therefore the firm will not produce more than 4 units.

6.5
PROFIT MAXIMISATION occurs where the difference between TR and TC is at a MAXIMUM (TR – TC)
Figure 6.5 provides a clearer picture of Profit Maximisation. Interpret it!
Interpretation of graph:

  • At all points where TR is above TC, the firm is making a profit.
  • At all points where TC is above TR, the firm is making a loss.
  • The gap between TR and TC represents profit.
  • Profit is maximised when the gap between TR and TC is the greatest.
    This is occurs at between 3 and 4 units.

6.5 Market structures

There are FOUR different market structures:

  • Perfect competition
  • Monopolistic competition
  • Oligopoly
  • Monopoly

Table 6.6 shows the 5 broad characteristics which distinguish the four market structures:
As you study each market structure in detail, you will be able to identify more distinguishing characteristics.

Characteristic Perfect competition  Monopolistic competition  Oligopoly Monopoly 
Number of businesses  Enough that a single business cannot influence the market price  A very large number  So few that each business must take the actions of the others into account One business
Nature of product  Homogenous (same kind)  Differentiated, e.g. cool drinks  Homogenous or differentiated Unique product without any close substitutes 
Market entry  Completely free   Free From free to restricted Blocked 
Control over price  None  Few  Considerable, but less than with a monopoly Considerable
Information   Complete Incomplete Incomplete Complete
Examples  International commodity markets, e.g. gold and oil  Fast-food outlets Petrol and oil markets Eskom

Table 6.6: The characteristics of different market structures
The illustration below shows the four different market structures:
6.6

6.6 Output, profit, losses and supply

6.6.1 The individual business
Short term equilibrium position
1. Economic profits
6.7

  • Given a market price of P3, profit is maximised where MR = MC = P3.
  • This occurs at a quantity of Q3.
  • At Q3 the firm’s average revenue (AR) per unit of production is P3,
  • The average cost per unit is C1 which is lower than the price of P3.
  • The firm is making an economic profit per unit of production of P3 – C1.

Another explanation

  • Total revenue equals P3 × Q3, therefore total revenue is represented by the area 0P3E3Q3.
  • Total cost equals C1 × Q3, this is represented by the area 0C1MQ3.
  • The difference between these two areas is the economic profit which is represented by the light grey shaded area C1P3E3M.

When Average Revenue is above Average cost the firm makes an ECONOMIC PROFIT.

2. Economic Losses
6.8

  • Given a market price of P3, profit is maximised where MR = MC at point E3.
  • This occurs at a quantity of Q3.
  • At Q3 the firm’s average revenue (AR) per unit of production is P3,
  • The average cost per unit is C3 which is higher than the price of P3.
  • The firm is making an economic loss per unit of production which is equal to the difference between C3 and P3.

Another explanation.

  • Total revenue equals P3 × Q3, therefore total revenue is represented by the area 0P3E3Q3.
  • Total cost equals C3 × Q3, this is represented by the area 0C3MQ3.
  • The difference between these two areas is the economic loss which is represented by the light grey shaded area C3P3E3M.
  • Whether the firm should continue production would depend on the level of AR (that is P3) relative to the firm’s average variable cost.

3. Normal profits

  • A firm makes normal profits when total revenue (TR) equals total costs or when average revenue (AR) equals average cost (AC).
  • Normal profit is the maximum return the owner of a firm expects to receive to keep on operating in the industry.

When Average Revenue is below Average Cost the firm makes an ECONOMIC LOSS.
When Average Revenue equals Average Cost the firm makes a NORMAL PROFIT.
6.9

  • Given a market price of P2, profit is maximised where MR = MC = P2.
  • This occurs at a quantity of Q2.
  • At Q2 the firm’s average revenue (AR) per unit of production is P2, which is also equal to the average cost per unit C2 (AC).
  • Since AR = AC, the firm earns a normal profit since all its costs are fully covered.
  • Point E2 is usually called the break-even point.

Another explanation

  • Total revenue equals P2 x Q2, therefore total revenue is represented by the area 0P2E2Q2.
  • Total cost equals C2 × Q2, this is represented by the area 0P2E2Q2.
  • Since Total revenue equals Total Cost the producer makes a normal profit.

The individual business can make an economic profit, economic loss or normal profit in the Short Run. They are referred to as short run equilibrium positions.
In the long run the individual business will always make normal profit.
6.6.2 The industry
The long term equilibrium for the industry and the individual firm
The impact of entry and exit on the equilibrium of the firm and industry

  • Profits are a signal for the entry of new businesses.
  • Losses are a signal for businesses to leave the market.
  • The long-term equilibrium in the perfect market will be influenced by the entry or exit of individual businesses.
  1. Entry into the apple market
    6.10
    • If individual farmers are earning an economic profit at P1.
    • New farmers will enter the market, more apples will be supplied.
    • The market supply curve will shift to the right from S1 to S2.
    • The Equilibrium price will drop from P1 to P2.
    • Individual farmers will then earn normal profits. There will be no further reason for new farmers to enter the market. The industry is in equilibrium.
  2. Exit from the apple market
    6.11
    • If individual farmers are making economic losses, some farmers may leave the industry.
    • When a few farmers leave the market, fewer apples will be supplied.
    • The market supply curve will shift to the left from S1S1 to S2S2.
    • The equilibrium price will increase from P1 to P2. Individual farmers will then earn normal profits. There will be no reason for individual farmers to leave the market.
    • Therefore in a perfect market the long term equilibrium is achieved when individual firms earn a normal profit.
  3. Longterm equilibrium – normal profit
    6.12

6.6.3 The supply curve of an individual firm
The short-run supply curve of an individual producer is that part of the marginal cost curve that is above the minimum average variable cost. This starts from shut-down point upwards. Below the shut-down point, the firm will not sell any goods. A firm will sell goods if the price is above the shutdown price level. This is shown in Figure 6.13 below:
6.13
6.6.4 Shut-down/closing down point
Shut-down point
A firm will shut down if it cannot meet its average or total variable costs.
Hence we conclude that:

ACTUAL SHUT-DOWN should only take place when:

  • TR < TVC
  • AR < AVC 

6.14

  • Point a: a firm will not produce here because AR < AVC
  • Point b: it is the lowest price that the firm will charge (shut-down point). It represents the beginning of the supply curve.
  • Point c: the firm is making an economic loss. Because AR < AC.
    The loss is minimised because the firm produces where MR = MC.
  • Point d: the firm is making normal profit (breaking even) because AR = AC.
  • Point e: the firm is making economic (supernormal) profits because AR > AC.

6.7 How to draw graphs to show various equilibrium positions

First draw your TWO axes: Price (P) on the vertical axis and Quantity (Q) on the horizontal axis. Remember, they meet at the origin (0). Note that the labelling of the axes is not the same for all graphs.
In showing the various equilibrium positions the following sequence should be followed.

  1. Draw the demand curve followed by the Marginal revenue curve, (in a perfect market D = MR = AR).
  2. Then draw the AC curve.
  3. Then draw the MC curve which must cut the AC curve at its minimum point.
  4. Identify profit maximising point. MC = MR
  5. Determine quantity (drop a line from the profit maximizing point to the x-axis).
  6. Determine price (extend line upwards from the profit maximizing point to the demand curve) and then extend the line horizontal to the y-axis.
  7. Compare AR/price to AC to determine profit or loss.

Everything is important – do not leave out anything! Each step counts for marks. Label all axes, curves and graphs.
Note the following:

  • To show economic profit the AC curve must cut the demand curve.
  • To show normal profit the minimum point on AC curve must be at a tangent to the demand curve.
  • To show economic loss the AC curve must not touch demand curve.

6.8 Competition policies

6.8.1 Description
Competition refers to the existence of free entry into and exit from markets.
This ensures that markets are not dominated by certain businesses.
6.8.2 Goals of competition policy

  • To prevent monopolies and other powerful businesses from abusing their power.
  • To regulate the formation of mergers and acquisitions who wish to exercise market power.
  • To stop firms from using restrictive practices like fixing prices, dividing markets etc.

6.8.3 The Competition Act in South Africa
The government introduced the Competition Act 89 of 1998 to promote competition in South Africa in order to achieve the following objectives:

  • promote the efficiency of the economy (its primary aim)
  • provide consumers with competitive prices and a variety of products
  • promote employment
  • encourage South Africa to participate in world markets and accept foreign competition in South Africa
  • enable SMMEs to participate in the economy
  • to allow the previously disadvantaged to increase their ownership of businesses

6.8.4 Institutions
The Competition Commission
It investigates restrictive business practices, abuse of dominant positions and mergers in order to achieve equity and efficiency in the South African economy.
The Competition Tribunal
It has jurisdiction throughout the Republic. It is a tribunal of record and independent from the other competition institutions.
The Tribunal’s main functions are to: grant exemptions, authorise or prohibit large mergers, adjudicate if any misconduct takes place, issue an order for costs on matters presented to it by the Competition Commission.
The Competition Appeal Court
Its status is similar to the High court. It has jurisdiction throughout the Republic and is a court of record.
Its main functions are to review orders made by the Competition Tribunal and amend or confirm these orders.

Activity 1
Study the diagram below and answer the questions that follow.
act1

  1. Define the concept market structure. (2)
  2. How many sellers will one find in a monopoly market? (2)
  3. In what market are all participants price-takers? Motivate your answer. (4)
  4. Explain the shape of the individual demand curve under perfect competition. (4)
  5. Under which market structure will you place the following businesses?
    • KFC
    • Eskom
    • Vodacom (6)
  6. Explain in your own words the message behind the pie-charts shown above. (4)

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Answers to activity 1

  1. Market structure refers to how a market is organised33 (2)
  2. One 33 (2)
  3. Perfect markets 33 there are too many producers and
    consumers for one producer to influence the price 33 (4)
  4. Horizontal to the quantity axis/perfectly elastic 3333 (4)
  5. KFC: monopolistic competition 33 Eskom: monopoly 33
    Vodacom: oligopoly 33 (6)
  6. Under perfect competition there are many sellers and
    buyers.3Under monopolistic competition there are many
    sellers and a few buyers.3 In the oligopoly there are many
    buyers but few sellers. 3 In a monopoly there is only one seller
    but many buyers.3 (4)

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Last modified on Wednesday, 08 September 2021 12:44