Cost of production- Buisness Economics PDF

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Cost of production- Buisness Economics...

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Cost of production

Meaning of cost Cost means whatever is sacrificed to obtain or produce something. In economics cost may be in monetary form like salaries to employees as well as in non-monetary form like real costs. Therefore, in economics the term cost is used in a wider sense while in financial accounting it is used in a narrower sense.

Opportunity costs / Economic costs / Alternative costs Opportunity cost means the value of the next best opportunity missed or given up to adopt another opportunity. For example: Rick has ` 10,000 to invest either in fixed deposit of a bank yielding 10% interest or in debentures of a company yielding 12% interest. He decides to invest in the debentures, then the opportunity cost of this investment is the interest on the fixed deposit forgone i.e. 10% of ` 10,000 = ` 1000.

Explicit costs These are the monetary payments made to outsiders for supplying raw materials, labour services, electricity, transportation facility etc. Salaries to employees, electricity bills, telephone bills, material purchase etc. are examples of explicit costs.

Implicit costs These are the monetary payments that self-owned could have earned if its alternative use was exercised. In fact they are opportunity costs.

Social costs These are the costs which are borne by a society as a whole. In fact, social costs are negative side effects arisen due to production of a good. For example: Factories emit smoke in the environment causing Air pollution, discharge their waste materials into rivers causing water pollution. Air pollution, water pollution affects the health of people negatively and therefore they are social costs. Real costs Real costs mean the pain and the discomforts felt, the sacrifices made by labour or entrepreneur while doing production or business. These costs are subjective costs i.e. they cannot be measured in money terms.

Fixed costs These are those costs which remain fixed irrespective the output level. In other words, those costs which do not change with the output level, then they are known as fixed costs. Rent of factory, insurance premium etc. are some examples fixed costs because they are fixed and whether output is zero or more, nevertheless they have to be paid. The fixed cost curve is a straight line parallel to the X-axis as shown in the figure.

FC

FC

0

Output

Variable costs These are those costs which change as the output level changes. If output is zero, then there is no variable cost. Raw material cost, labour cost, motive power etc. are variable costs because they increase as the output increases. In economics there is a special pattern of variable costs i.e. initially they are assumed to be increasing at decreasing rate then at moderate rate and finally at increasing rate. This pattern makes variable costs curve like inverted S. VC VC

0

Output

Total cost Total cost means the addition of total fixed costs (TFC) and total variable costs (TVC). Therefore, total cost can be defined as follows:

TC = FC + VC In economics there is a special pattern of total cost i.e. initially this is assumed to be increasing at decreasing rate then at moderate rate and finally at increasing rate. This pattern makes the total cost curve like inverted English letter S. One point must be noted here that the TC curve starts from where the FC curve starts.

TC/TVC/FC

TC = TFC +TVC

TVC

FC 0

Output

Marginal Cost (MC) When output is increased from one level to another level, then the total cost changes and this change in the total cost is termed as marginal cost. Mathematically, marginal cost is defined as the ratio of change in total cost ant change in output.

MC=

∆ TC ∆Q

Using calculus we can define the marginal cost as follows: Suppose that C = f (Q) is a total cost function, then

MC=

d ( TC ) … … …… … … .(1) dQ

Since

TC =TVC + TFC Therefore

MC=

d d ( TVC + TFC ) = ( TVC ) … … … … … … .(2) dQ dQ

Equation (1) states that the marginal cost is the derivative of the cost function with respect to the output and equation (2) states that the marginal cost is the derivative of the total variable cost function with respect to the output. Thus, the marginal cost can be calculated using either the total cost or the total variable cost. Apart, since the derivative of a function gives its slope, therefore marginal cost can also be defined as the slope of the TC curve or the TVC curve. In economics the MC curve looks like English letter “U” as shown in the figure. MC MC

0

Output

Reason of the U-shaped: The MC curve is U shaped because of the law of variable proportion. In fact marginal cost is also defined as the ratio of labour wage rate “w” and the marginal production of labour MPL. Therefore,

MC=

w MP L

Now we know that the law of variable proportion states that the MP L increases in the first stage and decreases in the second stage. Therefore, mathematically in the first stage when the MP L increases, then the above ratio of w and MP L i.e. MC must decrease and in the second stage when the MP L decreases, then the above ratio must increase. In this way, in the first stage the MC curve falls and in the second stage the MC curve increases causing it U shaped. This is all shown in the following diagram. MPL

First stage

Second stage

MC

First stage

Second stage

Labour

Output

Average Fixed Cost (AFC) AFC is defined as the ratio of total fixed cost and total output. Therefore,

AFC =

FC Q

AFC curve is downward sloping and never touches the X-axis because fixed cost is not zero. In this way the AFC curve is a rectangular hyperbola.

AFC

AFC 0

Output

Average Variable Cost (AVC) AVC is defined as the ratio of total variable cost (TVC) and total output (Q). Therefore,

AVC=

VC Q

Reason of the U-shaped: The AVC curve is U shaped because of the law of variable proportion. In fact AVC is also defined as the ratio of labour wage rate “w” and the average production of labour AP L. Therefore,

AVC=

w AP L

Now we know that the law of variable proportion states that the AP L increases in the first stage and decreases in the second stage. Therefore, mathematically in the first stage when the AP L increases, then the above ratio of w and AP L i.e. AVC must decrease and in the second stage when the APL decreases, then the above ratio must increase. In this way, in the first stage the AC curve falls and in the second stage the AVC curve increases causing it U-shaped. This is all shown in the following diagram.

APL

First stage

Second stage

AVC

First stage

Second stage AVC

APL Output

Labour

Average cost Average cost is defined as the ratio of total cost and total output. Symbolically,

AC=

TC Q

Average cost is also defined as the sum total of average fixed costs and average variable costs. Therefore,

AC = AFC + AVC In economics the AC curve looks like English letter “U” as shown in the figure.

AC AC

0

Output

Reason of the U-shaped: The AC curve is U shaped because of the law of variable proportion. In fact AC is also defined as the ratio of labour wage rate “w” and the average production of labour APL plus AFC. Therefore,

AC= AFC +

w AP L

Now we know that the law of variable proportion states that the AP L increases in the first stage and decreases in the second stage. Therefore, mathematically in the first stage when the AP L increases, then the ratio of w and APL i.e. AVC must decrease and in the second stage when the AP L decreases, then the ratio must increase. In this way AVC gets Ushaped. Further we also know that AFC curve is downward sloping and reaches to zero and therefore adding AFC to AVC creates the same shape as that of AVC. In this way, in the first stage the AC curve falls and in the second stage the AVC curve increases causing it U-shaped. This is all shown in the following diagram.

Relationship between MC and AC There are three relationships between MC and AC 1. When MC < AC, then AC falls. 2. When MC = AC, then AC is minimum is at point E. 3. When MC > AC, then AC rises.

AC/MC

MC

AC

E

0

Output

Logic / Rationale / Reason / Cause of the above relationships Suppose that you have three subjects Mathematics, Economics and Accountancy in which your grades are 10, 15 and 20 respectively, then the average grade should be

10 + 15+ 20 45 = =15 3 3 Now suppose that your are given the fourth subject Statistics in which your grade is 7, then the new average should be

10 + 15+ 20 + 7 52 = =13 4 4 Now if your grade in the fourth subject were 18, then the new average should be

10 + 15+ 20 + 25 4

70 = 4 =17.5

It is obvious that, when the grade in the fourth subject i.e. 7 is less than the initial average grade i.e.15, then the new average is falls to 13 and when the grade in the fourth subject i.e.18, is greater than the initial average grade i.e.15, then the new average increases to 17.5. This is the mathematics of average and additional (or marginal) grades which is exactly the same as the mathematics of average cost and marginal cost. Thus when the marginal cost remains less than the old average cost, then the new average cost falls and when the marginal cost remains more than the old average cost, then the new average cost increases.

For the lovers of Mathematics (OPTIONAL) Mathematical Proof of the above relationships Suppose that TC = f (Q) is a cost function in which TC is the total cost and Q is the output. We know that the average cost is defined as:

AC=

TC Q

Differentiating AC with respect to Q we get

( )

d d TC ( AC )= dx dx Q

Applying the quotient rule in the right hand side of the equation

(

1 d d d TC−TC Q ( AC )= 2 Q dx dQ dQ Q

)

We know that

Marginal cost=MC=

d TC dx

Therefore

1 d ( AC )= 2 (Q× MC−TC ) dx Q

(

d ( AC )= Q 2 MC − TC Q dx Q

)

1 d ( AC )= ( MC − AC ) dx Q Now we are able to derive the following conclusions from the last equation: 1. When MC AC, then the slope of the AC is positive i.e. the AC curve must be increasing

Relationship between MC and AVC There are three relationships between MC and AVC 1. When MC < AVC, then AVC falls. 2. When MC = AVC, then AVC is minimum at point E. 3. When MC > AVC, then AVC rises. AC/MC

MC

AVC

E

0

Output

Logic / Rationale / Reason / Cause of the above relationships Suppose that you have three subjects Mathematics, Economics and Accountancy in which your grades are 10, 15 and 20 respectively, then the average grade should be

10 + 15+ 20 45 = =15 3 3 Now suppose that your are given the fourth subject Statistics in which your grade is 7, then the new average should be

10 + 15+ 20 + 7 52 = =13 4 4 Now if your grade in the fourth subject were 18, then the new average should be

10 + 15+ 20 + 25 70 = =17.5 4 4 It is obvious that, when the grade in the fourth subject i.e. 7 is less than the initial average grade i.e.15, then the new average is falls to 13 and when the grade in the fourth subject i.e.18, is greater than the initial average grade i.e.15, then the new average increases to 17.5. This is the mathematics of average and additional (or marginal) grades which is exactly the same as the mathematics of average variable cost and marginal cost. Thus when the marginal cost remains less than the old average variable cost, then the new average variable cost falls and when the marginal cost remains more than the old average variable cost, then the new average cost increases.

For the lovers of Mathematics (OPTIONAL) Mathematical Proof of the above relationships Suppose that TVC = f (Q) is a variable cost function in which TVC is the total variable cost and q is the output. We know that the average variable cost is defined as:

AVC=

TVC Q

Differentiating AVC with respect to Q we get

( )

d TVC d ( AVC )= dx dx Q

Applying the quotient rule in the right hand side of the equation

(

1 d d d ( AVC )= 2 Q Q TVC−TVC dQ dx dQ Q

)

We know that

Marginal cost=MC=

d TVC dx

Therefore

1 d ( AVC )= 2 ( Q× MC−TVC ) dx Q

(

1 d TVC ( AVC )= MC − Q Q dx

)

d AVC = 1 ( ) ( MC − AVC ) Q dx Now we are able to derive the following conclusions from the last equation: 1. When MC AVC, then the slope of the AVC is positive i.e. the AVC curve must be increasing

AC, AVC and MC together

AC/MC

MC AC

0

AVC

Output

Long rrun un cost Long run average cost (LAC): Its derivation Or Relationship between the long run cost and the short run cost. Suppose there are three plants x, y and z with the short run average cost curves SACx, SACy and SACZ respectively such that x is a small plant, y is a medium plant and z is a large plant. Now if the producer wants to produce the output Q 1, then he has two options i.e. either produce at plant x or plant y. If plant y is selected, then the average cost is AC A corresponding to point A on SACx and if plant y is selected, then the average cost is AC B corresponding to point B on SACy. From the figure, this is obvious that ACA < ACB, therefore he should produce at plant x. In this way, he has point A at which he minimizes his average cost. Similarly, if he wants to produce the output Q 2, then plant y is better because the average cost at plant x (i.e. ACD corresponding to point D on SACx) is greater than the average cost of plant y (i.e. AC C corresponding to point C on SACY). In this way, he has point C at which he minimizes his average cost. Now, if the producer wants to produce the output Q3, then plant z is better because the average cost of this plant (i.e. AC F corresponding to point F on SACy) is greater than the average cost of plant z (i.e. ACE corresponding to point E on SACz). In this way we can find others cost minimizing points on these plants. By joining these points we get a curve known as the long run average cost curve. In the diagram, the crosshatched parts of the short run average cost curves constitute the long run average cost curve. However, if there were “ n” number of plants instead of just three, then the long run average cost curve would have been the dark curve labeled as LAC. Since the long run average cost curve LAC envelops the short run average cost curves, therefore the curve (LAC) is also known as the “envelope curve”. This curve is also known as the “planning curve” because the producer is able to plan the plant to be used for a given amount of production. Average cost D

AC

SACx SACy

AC F AC B AC A

F B

A

AC E AC C

0

LAC SACz

E C

Q1

Q2

Q3

Output

Why is LAC downward sloping? Or Explanation of the downward portion of LAC LAC is downward sloping up to a certain point of output because of the economies of scale. Economies of scale of mean the benefits or reduction in cost due to operating at large scale. Economies of scale are classified into two categories. These categories are: 1. Internal Economies: These are those economies which accrue to the firm increasing the scale i.e. such economies are enjoyed by that firm only which has increased its scale not by the industry as whole. Internal economies may include: a. Managerial economies In a large firm, the managers can concentrate on the important decisions i.e. strategic decisions etc. Routine jobs or tasks can be allocated or delegated to the other persons who are qualified in their respective fields. Thus, large scale production means better use of and greater specialization in management. But in a small organization, a specialist may have to divide his or her time between several executive functions like marketing, accounts, human resource etc. A larger scale of production means the sales expert can supervise sales related work full time, while appropriate specialists perform other managerial functions. It results in greater efficiency and lower per unit cost. b. Specialization and division of labour When the scale of production expands, then there is division of labour i.e. the entire work is divided into various tasks among the specialists. As a result, a worker does only that task in which he or she is specialized. It results in the productivity of labour and reduces time. c. Technical economies Large firms are able to afford the latest, sophisticated, automatic machines and technology of production which small firms can not afford. Although the fixed costs in such machines and technology increase, yet average cost lowers because the total cost is allocated over a large amount of output. d. Marketing economies When the production of a firm expands, then it needs raw material in more quantity than before. As a result, big orders of raw materials are placed with the suppliers who are ready to give quantity discounts. These quantity discounts reduce the cost of material. Apart, big quantity of raw materials cause the transport cost to decline because the carriers operators are generally ready to facilitate the transport at lower rates. Reducing costs make the firm able to reduce its selling price e. Credit economies / Finance economies Large firms need huge money for their fixed capital requirement and working capital requirement. Such firms can issue debentures at large scale, therefore can secure finance from banks at lower interest rates which is very difficult in case of small firms. It reduces the cost of finance. f.

Inventory economies

A large firm is able to maintain safety stock in large quantity and therefore when there is a shortage in the supply of raw material and the raw material is sold by the suppliers at very high prices, nevertheless the production does not stop. The firm is able to produce at lower cost than the small producers who are not able to maintain safety stock in a large quantity.

2. External Economies According to Cairn Cross, “External economies are those which are shared in by a number of firms or industries when the scale of production in any industry of group of industries increases.” The main types of external economies are as follows: a. Economies of concentration of an industry When various firms belonging to a particular industry club at a particular place, then this is known as the localization of industry or concentration of an industry. Such localization of an industry may be due to the easiness in availability of the raw materials or other inputs, better government laws or facilities, transport system etc. For example: Bollywood in Mumbai, tea industry in Assam, jute industry in Bengal etc. Localization of an industry results in certain advantages accruing to the firms externally. b. Economies of information When an industry expands, then the availability of necessary, useful and qualitative information is available easily. Firms may agree to spend money o...