2. Lecture Plan
• Objectives
• Introduction
• Kinds of Costs
• Costs in Short Run
• Costs in Long Run
• Costs of a Multi Product Firm
• Costs of Joint Products
• Linkage between Cost, Revenue and Output through Optimization
• Break Even Analysis
• Economies of Scale
• Economies of Scope
• Costs and Learning Curves
3. Objectives
• To understand the meaning of cost in economic analysis and
its relevance in managerial decision making.
• To explain different types of costs, with focus on the
difference between economic and accounting philosophies.
• To analyze the importance of matching costs with relevant
time frames and to understand the short and long run costs.
• To help develop an understanding of estimation of cost
functions.
• To introduce the concepts of economies of scale, economies
of scope, break even analysis and learning curve.
4. Introduction
• Cost is defined in simple terms as a sacrifice or foregoing which has
already occurred or has potential to occur in future with an objective to
achieve a specific purpose measured in monetary terms.
• Cost results in current or future decrease in cash or other assets, or a
current or future increase in liability.
• Determinants of cost:
– Price of inputs
– Productivity of inputs
– Technology
– Level of output
• Mathematically we can express the cost function as:
C= f(Q, T, Pf)
where C=cost; Q=output; T=technology; Pf = price of inputs.
5. Kinds of Costs
• Accounting Costs/ Explicit Costs/ Out of Pocket Costs
– Which can be identified, measured and accounted for; e.g.
cost of raw materials, wages and salary and capital costs
like cost of the factory building.
– Which result in cash outflow or increase in liability
• Real Costs
– More or less social and psychological in nature and non
quantifiable in money terms; e.g. cost of sacrificing leisure
and time.
– Not considered by accountants.
• Opportunity Costs
– Help in evaluation of the alternative uses of an input other
than its current use in production
6. Kinds of Costs
• Implicit Costs
– Do not involve cash outflow or reduction in assets, or increase in
liability; e.g. owner working as manager in own building
– Important for opportunity cost measurement
• Direct Costs
– Which can be attributed to any particular activity, such as cost of raw
material, labour, etc.
• Indirect Costs
– Costs which may not be attributable to output, but are distributed
over all activities are indirect costs
– Also known as overheads.
• Replacement costs
– Current price or cost of buying or replacing any input at present.
• Social Costs
– Costs to the society in general because of the firm’s activities. E.g.
pollution caused by industrial wastes and emissions.
7. Kinds of Costs
• Historic Costs/ Sunk Cost
– Incurred at the time of purchase of assets; no longer relevant for
decision making
• Future Costs
– Opposite of historic costs and are budgeted or planned costs.
– Not included in the books of accounts.
• Controllable Costs and Uncontrollable Costs
– Controllable Costs are subject to regulation by the management of a
firm; e.g. fringe benefits to employees, costs of quality control.
– Uncontrollable Costs are beyond regulation of the management; e.g.
minimum wages are determined by government, price of raw material
by supplier.
• Production Costs and Selling Costs
– Production Costs are estimated as a function of the level of output
– Selling costs occur on making the output available to the consumer.
8. • Fixed Costs
– Do not vary with output; e.g.
plant, machinery, building.
– Total Fixed Cost (TFC) curve is a
straight line, parallel to the
quantity axis, indicating that
output may increase to any
level without causing any
change in the fixed cost.
– In the long run plant size may
increase hence FC curve may
be step like, where each step
showing FC in a particular time
period.
Costs in Short Run
O
Costs
Quantity
Costs
O
Quantit
y
TFC
C
TFC
9. Costs in Short Run
TVC
TC
TFC
O
Costs
Quantit
y
Variable Costs
Costs that vary with level of
output and are zero if no
production; e.g. cost of raw
materials, wages.
Normally TVC is like a straight
line starting from origin.
TVC may be an inverse S
shaped upward sloping curve,
due laws of variable
proportions.
Total cost (TC)
Sum of TFC and TVC
Slope of TC curve is
determined by that of the TVC.
TFC
Costs
O
Quantit
y
TVC
TC
10. Average and Marginal Cost
• Average Cost (AC) is total cost per unit of output.
– AC is equal to the ratio of TC and units of output. (TC/Q)
– AC=AFC+AVC
• Average Fixed Cost (AFC) is fixed cost per unit of output
(AFC= TFC/Q)
• Average Variable Cost (AVC) is variable cost per unit of output
(AVC= TVC/Q)
• Marginal cost (MC) is the change in total cost due to a unit
change in output.
– MCQ= TCQ- TCQ-1
• Since the fixed component of cost cannot be altered, MC is
virtually the change in variable cost per unit change in
output.
– Also known as rate of change in total cost.
11. Average and Marginal Cost Functions
• AC curve is U shaped
• When both AFC and AVC fall, AC
also falls and when AVC rises AC
starts increasing.
• When average costs decline, MC
lies below AC.
• When average costs are constant
(at their minimum), MC equals
AC.
– MC passes through the
lowest point of AC curves.
• When average costs rise, MC
curve lies above them.
Contd…
MC
AVC
AC
AC/MC
Quantity
O
AFC
12. Costs in Long Run
• All costs are variable in the long run since factors of
production, size of plant, machinery and technology can be
varied in the long run.
• The long run cost function is often referred to as the “planning
cost function” and the long run average cost (LAC) curve is
known as the “planning curve”.
• As all costs are variable, only the average cost curve is relevant
to the firm’s decision making process in the long run.
• The long run consists of many short runs, therefore the long
run cost curve is the composite of many short run cost curves.
13. Costs in Long Run
MC2
SAC2
MC3
SAC3
q0 q1 q2
MC1
SAC1
LAC
AC, MC
Quantity
O
In the long run the firm may increase plant size to increase output.
As output is increased from q0 to q1 capacity at SAC1 is overworked.
Hence the firm shifts to a higher plant size SAC2.
This shift would lower the average cost of the firm.
The same process would be repeated if the firm increases its output
further to q2.
It shows scalloping curve as the plant costs are not smoothened.
14. Long Run Average Cost
• The LAC function can be shown as an envelope curve of the short run cost
functions.
• Each of the SAC curves represents the cost conditions for a plant of a
particular capacity.
• LAC curve envelopes SAC1, SAC2, SAC3, showing the average cost of
production at different levels of output turned out by plants 1, 2 and 3.
• LMC curve corresponds to LAC curve.
SMC3 SAC3
q1 q2
LAC
SAC1
SMC1
SMC2
SAC2
LMC
q3
AC, MC
Quantity
O
15. Long Run Marginal Cost
• Long run marginal cost (LMC) curve joins the points on the
short run marginal cost (SMCs) curves that are associated
with short run average costs corresponding to each level of
output on the LAC curve.
• The optimum plant size is II, assuming sufficient demand.
• Optimal level of output is Oq*, where long run and short run
marginal and average costs are all equal.
• LMC must be less than LAC when the latter is decreasing
• It would be equal to LAC when the latter reaches its
minimum.
• LMC is greater than LAC when the latter is increasing.
16. Costs of a Multi Product Firm
Q
Q
X
C
Q
X
C
F )
(
)
( 2
2
1
1
• Assuming that a multi product firm manufactures two goods, with the same
plant and machine.
• Total cost (TC) of production would be the sum of TFC and the total of
variable costs (C1 and C2) of producing both the products, times the
quantities of the two goods (Q1 and Q2).
TC= TFC+C1Q1+ C2Q2
• If the two products are produced in fixed proportions, then we can use the
concept of weighted average cost (ACw) defined as:
ACw (Q)=
(where X1 and X2 are the proportions in which products 1 and 2 are
produced (or the weights used in calculating average costs) and Q is the
total output. )
17. Costs of Joint Products
• Two or more products undergo the same production process up to a split
off; i.e. if one good is produced the other will automatically be produced;
e.g. agriculture, minerals.
• Common costs
– Cannot be identified with a single joint product.
• Separable costs
– Can be identified with a particular joint product.
– Incurred for the product separated beyond the split off point.
Methods of allocating common costs
• Physical measure
– Common costs are allocated in proportion to a physical measure
identified to describe the quantity of each product obtained at the split
off point.
• Sales value at split off
– Common costs can be allocated in proportion to the sales value of the
products after split off point.
18. Linkage between Cost, Revenue and Output
Total Revenue (TR)
• The total amount of money received by a firm from goods sold (or services
provided) during a certain time period.
TR=Q.P, where Q is the quantity sold and P is the price per unit.
Average Revenue (AR)
• Revenue earned per unit of output sold.
AR=TR/Q =P
Marginal Revenue (MR)
• Revenue a firm gains in producing one additional unit of a commodity.
• Calculated by determining the difference between the total revenues
produced before and after a unit increase in production.
MRQ= TRQ- TRQ-1; or
MR=
dQ
dTR
19. Relationship between TR and MR
• TR curve has the shape of an
inverted U, starting from the
origin, and dipping across the
quantity axis after reaching a
maximum.
– TR will be zero when nothing
is sold, and zero again when
a great deal is sold at a zero
price.
• MR is the slope of the TR curve.
• Rise in the total revenue curve is
the change in total revenue with
rise in level of output.
MR
TR Quantity
Price,
Revenue
O
Price,
Revenue
O
Quantity
20. Relationship between AR and MR
• AR curve can have the following positions:
– AR is a straight line, MR will lie midway to AR
– AR is convex to the origin, MR will lie less than midway to AR
– AR is concave to the origin, MR will lie more than midway to AR
MR
AR AR
MR
AR
MR
Quantity
MR/AR
O Quantit
y
MR/AR
O
Quantit
y
MR/AR
O
21. Break Even Analysis
AVC
P
TFC
• Examines the relation between total revenue, total costs and total profits
of a firm at different levels of output.
• Used synonymously with Cost Volume Profit Analysis.
• Breakeven point is the point where total cost just equals the total
revenue, in other words it is the no profit no loss point.
Approaches to break even analysis:
• Algebraic Method
– If P be the price of a good, Q the quantity produced’ the breakeven
output is where total revenue equals total cost (Q* ).
Total Revenue= P.Q
Total Cost= TFC+TVC = TFC+AVC.Q
P.Q*=TFC+AVC.Q*
(P-AVC)Q*=TFC
Q*=
22. Break Even Analysis
Contribution Margin
• Represents that portion of the price of the commodity produced by the
firm that can cover the fixed costs and contribute to profits.
Contribution Margin = P - AVC
Profit Volume (PV) Ratio
• Also defined as the ratio of marginal change in profit and marginal change
in sales.
PV Ratio=
• Using PV ratio also, Break even point =
Margin of Safety
• Margin of Safety = Planned sales – Breakeven sales
Sales
on
Contributi
PVratio
FC
23. Break Even Analysis
Graphical Method
• Plot cost and revenue on the Y axis
and output on the X axis.
• TC is a straight line because AVC is
assumed to be constant
• Total revenue is proportional to
output and the TR is a straight line
through the origin.
• Point of intersection of TR and TC
(E) is the Break Even point, i.e. no
profit no loss at output Q*
– Prior to E is loss zone
– After E is the profit zone.
• Shows the profit (or loss) resulting
from each level of sales by the
firm.
FC
TC
TR
O Output
Cost,
Revenue
E
Q
*
VC
Profit
Loss
24. Economies of Scale
• Economies of scale refers to the efficiencies associated with
larger scale operations
• This level is reached once the size of the market is large
enough for firms to take advantage of all economies of
scale.
• Two types of economies of scale:
– Internal economies (which occur to the firm due to large size of
operations);
• e.g. Division of labour/ specialization, Financial economies,
better managerial functions.
– External economies (which occur due to expansion of the industry,
and the firm also benefits).
• Technological advancement, development of infrastructure
pool of skilled workers
25. Economies of Scope
• When the production capacity can be utilised for producing more than one
goods, average costs are less as compared to when they are produced by
different firms separately; e.g. Computers and printers; heavy vehicles and
light vehicles.
• Practice of economies of scope to business strategy is heavily based on the
development of high technology.
• Globalization has made such economies even more important to firms in
their production decisions.
• Measured by the ratio of average costs to marginal costs, when the firm
produces joint or multiple products.
• Assume three products at individual costs of C1, C2 and C3, while Ct is the
total cost when the three activities are carried out together, the Scope Index
(S):
3
2
1
3
2
1
)
(
C
C
C
C
C
C
C t
S =
26. Cost and Learning Curves
• In economics learning by doing refers to the process by which producers
learn from experience.
• The concept of learning curve is used to represent the extent to which
average cost of production falls in response to increase in output.
• The equation of learning curve can be expressed as:
C=AQb
(where C is the cost of input for the Qth
unit of output produced and A is the cost of
the first unit of output obtained).
• Since increase in cumulative output leads to a decrease in cost, “b” has a
negative value.
• Logarithmic form of this equation is :
ln C= ln A + b.ln Q,
(where b is the slope of the learning curve).
27. Summary
• Any production process must incur costs. Direct or variable costs vary with the level
of output; fixed costs remain at the same level, irrespective of the rate of production.
• The costs of a firm include accounting, real and opportunity costs. Financial
management recognizes only accounting costs or nominal cost that can be recorded
in the books of accounts.
• The short run is the period within which some obligations associated with
management, plant, and equipment are not alterable by changing the firm's
managerial capacity or scale of operations.
• In the long run all aspects of the firm's operations can be adjusted; so all costs are
variable in the long run.
• The long run average cost (LAC) curve is a planning horizon, which envelopes the
firm's short run AC curves associated with different plant sizes.
– Determination of the average cost of a multi product firm can be done with the method of
weighted average cost, if the two products are produced in fixed proportions.
• Allocation of common costs to the joint products can be done by physical measure of
outputs or by sales value at the spilt off point.
• Breakeven analysis deals with determining profit at various projected sales volume
levels, identifying the breakeven point, and making a managerial decision regarding
the relationship between likely sales and breakeven point.
28. Summary
• Total Revenue is the total amount of money received by a firm from goods sold (or
services provided) during a certain time period. Average Revenue is the revenue
earned per unit of output sold.
• Marginal Revenue is the revenue a firm gains in producing one additional unit of a
commodity. Profit is the difference between Total Revenue and Total Cost; the profit
function shows a range of outputs at which the firm makes positive (or supernormal)
profits.
• Economies of scale refer to the efficiencies associated with larger scale operations; it
is a situation in which the long run average costs of producing a good or service
decrease with increase in level of output.
• Economies of scope refer to a situation in which average costs of manufacturing a
product are lower when two complementary products are produced by a single firm,
than when they are produced separately.
• Learning by doing refers to the process by which producers learn from experience,
while technological change is an increase in the range of production techniques that
provides new vistas to producing goods.