This document discusses the concepts of fixed costs, variable costs, total costs, average costs and marginal costs for a firm in the short run. It defines each type of cost and provides tables and graphs to illustrate how costs change with different levels of output. The key points are: - Fixed costs remain constant in the short run, while variable costs change with output. Total costs are the sum of fixed and variable costs. - As output increases, average fixed costs fall while average variable costs first fall and then rise, resulting in the U-shaped average total cost curve. - Marginal costs first fall and then rise, and equal average costs at the minimum point of the average cost curve.

1. 1
Prepared By: Birendra Guragain
UNIT-4
REVENUE CURVE AND COST
Overview
A firm produces goods it has to incur expenses. Such expenses are payments to labor, land
owners, capital, purchase of raw materials, fuels etc. Cost is concerned with a financial aspect
of production. A firm produces goods it has to incur expenses. Such expenses are payments
to labor, land owners, capital, purchase of raw materials, fuels etc. Cost is concerned with
financial aspect of production. There are different types of cost in economics. Among them,
the concept of fixed and variable costs are discussed. Fixed Cost The expenses made for
setting up the production plant are the fixed cost. It doesn’t change in the short time period
and also doesn’t depend on the quantity of production. For e.g.: cost of machinery, building,
managerial team etc. are the fixed cost. It is also known as overhead cost or supplementary
cost. Variable Cost Variable cost is the one which changes along with the quantity
production. For e.g. expenses for raw material, energy use, daily wage labor etc. are the
variable cost. Thus, variable cost is those which vary with variation in the total output.
Fixed & Variable Cost and Short & Long Run Cost
Concept of cost
A firm produces goods it has to incur expenses. Such expenses are payments to labor, land
owners, capital, purchase of raw materials, fuels etc. Cost is concerned with financial aspect
of production. There are different types of cost in economics. Among them, the concept of
fixed and variable costs are discussed.
Fixed Cost
The expenses made for setting up the production plant are the fixed cost. It doesn’t change in
the short time period and also doesn’t depend on the quantity of production. For e.g.: cost
of machinery, building, managerial team etc. are the fixed cost. It is also known as overhead
cost or supplementary cost.
Variable Cost
Variable cost is the one which changes along with the quantity production. For e.g. expenses
for raw material, energy use, daily wage labor etc. are the variable cost. Thus, variable cost is
those which vary with variation in the total output.

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Short Run
The short run is a period of time in which one factor of production is fixed so that the firm
can change its output by changing the variable factors only. The firm in the short run cannot
alter fixed inputs because it is technically difficult to do so in the short period. If the firm
wants to expand then it will cost high.
Long Run
The long run is a period of time in which all factors are variable. In the long run, the inputs
don't remain fixed and the firm can take decision easily. The firm can change its output by
altering the firm’s plant size, altering capital input or even changing the plant size.
Short-Run Cost Curves
Total Fixed Cost (TFC)
Total fixed cost is fixed cost which must be incurred by a firm in the short run, whether the
output is small or large. They are those cost, which is fixed in volume for certain given
output. It includes expenditure made on land, building, machinery, administrative expenses,
insurance fee, and so on.
Total fixed cost (TFC) is explained with the help of the table.
Outputs (in units) TFC (in Rs.)
0 10
1 10
2 10
3 10
4 10
The above table shows that total fixed cost remains the same at every level of income. The
cost is Rs.10 when the output unit is 0. When the output increases from 0 to 1, the cost is still
the same i.e. Rs.10. Similarly, the output goes on increasing and reaches to 4 units but the
cost is fixed to Rs.10. It can be shown from the following figure:

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Fig: TFC Curve
The above figure shows, TFC curves represent the total fixed cost curve, which is parallel to
the horizontal axis as it remains constant at a different level of output. Here, the TFC is fixed
in OP when the level of output increases from OQ, OQ1, OQ2 and OQ3.
Total Variable Cost (TVC)
Total variable cost is those cost which is incurred on the employment of variable factors of
production whose amount can be altered in the short run. TVC is the cost incurred on the
variable factor like raw material, energy supply, direct labor etc.
TVC can be explained with the help of the following table:
Output (in units) TVC (in Rs.)
0 0
1 10
2 18
3 24
4 28
5 38
6 50
The above table shows that TVC is 0 when the output is 0. As the production began, TVC
increases significantly in the 1st phase due to the inefficiency of management, labor forces or
operation module of machinery and equipment. After this, TVC rises up slowly which is seen
up to 4 units of production in the given table. After 4 units, TVC again increases. So, as a
result of heavy maintenance cost, TVC rises up rapidly.

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Fig: TVC Curve
The above figure shows the total variable cost curve. TVC is zero at starting when no output
is produced. When the output rises, the TVC curve forms an inverse shape due to the
operation of a law of variable proportions. At a low level of output and again rises more than
the rise in output. Later on, TVC rises less than the rise in output and again rises more than
output.
Total Cost (TC)
Total cost is the sum of total fixed cost (TFC) and total variable cost (TVC) in the short run.
It gives the total cost of production of the firm in the short run. The total cost of production
changes with the change in total variable cost as it changes with the level of output.
i.e. TC = TFC + TVC
Total cost can be explained with the following table:
Output in
units
TVC TFC TC
0 0 10 10
1 10 10 20
2 18 10 28
3 24 10 34
4 28 10 38
5 38 10 48
6 50 10 60

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The above table shows that the total fixed cost remains constant with every increase in
output. The total variable cost increases with the increase in the level of output. Total cost
(TC) is obtained by adding TFC and TVC. TC increases with the every increase in output
pushed by TVC. Hence, TC and TVC has a positive relation.
It can be shown with the help of the following figure:
Fig: Total Cost Curve
The above figure shows that TC, TVC, and TFC curve represents the total cost curve, total
variable cost curve, and total fixed cost curve respectively. TC curve starts from the point
where TFC curve starts. But when output rises, TC rises since variable costs come into
operation. So, TC curve takes the shape of TVC curve.
Short-Run Average Cost Curves

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Average Fixed Cost (AFC)
Average Fixed Cost (AFC) is defined as total fixed cost divided by the level of output
produced. It is the per unit production of fixed cost. Thus,
AFC =
𝑇𝐹𝐶
𝑄
Where,
AFC = Average Fixed Cost
TFC = Total Fixed Cost
Q = Level of output
As a fixed cost remains constant dividing by an increasing output would gradually reduce the
average fixed cost. It can be shown from the following figure:
In the above figure, AFC is the average fixed cost. AFC curve drops lower as the output
expands, when AFC becomes very large it approaches the horizontal axis but never touches
the x-axis.
Average Variable Cost (AVC)
Average Variable Cost is defined as the total variable cost divided by the level of output
produced. Thus,
AVC =
𝑇𝑉𝐶
𝑄
Where,

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AVC = Average Variable Cost
TVC = Total Variable Cost
Q = Level of output
The average variable cost will generally fall as the output increases. It can be explained with
the help of the following figure:
In the figure, AVC represents Average Variable Cost. It slopes downward, in the beginning,
reaches a minimum point and rises upward thereafter.
Average Total Cost (ATC)
Average total cost is defined as the total cost divided by the level of output produced. It can
also be defined as the sum of average fixed cost and average variable cost. Symbolically,
ATC =
𝑇𝐶
𝑄
=
𝑇𝐹𝐶
𝑄
+
𝑇𝑉𝐶
𝑄
= AFC + AVC
Where,
ATC = Average Total Cost
AFC = Average Fixed Cost
AVC = Average Variable Cost
TC = Total Cost

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Q = Quantity produced
Average total cost gives us the total cost per unit of production. It can be shown in the figure:
In the above figure, ATC represents Average Total Cost. In the beginning, ATC declines and
reaches its minimum point as the utilization of plant reaches maximum. Thereafter ATC
starts rising due to diseconomies of scale and it takes a 'U' shape.
Marginal Cost (MC)
Marginal cost is the increase or decrease in total production cost if output is increased by one
more unit. Thus,
MC =
ΔTC
ΔQ
Where,
MC = Marginal Cost
ΔTC = Change in Total Cost
ΔQ = Change in output
The marginal cost of the second unit of output is obtained by subtracting the total cost of one
unit from two unit of output produced.
MC2 = TC 2 - TC1
The marginal cost curve can be shown from the following figure:

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Fig: Marginal Cost Curve
In the above figure, the marginal cost first falls, reaches minimum and thereafter increases.
Thus an MC curve also first slope downward reaches the minimum and rises thereafter.
Relation between AC, AFC, AVC and MC
The relation between AC, AFC, AVC and MC can be shown from the following figure:
Fig: Relation between AC, MC, AFC and AVC
In the above figure, AFC falls continuously approaching both the axes. In the beginning,AVC
falls, reaches minimum and then starts rising at the fourth unit of output. When AVC is at
minimum MC equals AVC. When AFC approaches the horizontal axis, AVC approaches
ATC. Thus ATC = AFC + AVC. When ATC is at a minimum, MC = ATC. When both AVC

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and ATC curves are falling MC curve lies below them. It lies above them when they are
rising therefore, MC cut AVC and AC respectively from below.
Relationship between AC and MC
There is a close relationship between AC and MC. MC is the change in TC resulted from the
change in the production of one more unit of output whereas AC is the total cost divided by
the output. Both AC and MC are derived from TC.
Symbolically;
MC = ∆TC / ∆Q
AC = TC / Q
The relationship between these two can be explained with the help of the following diagram:
In the above figure, SMC represents the short-run marginal cost curve and SAC represents
the short-run average cost curve. SMC and SAC intersect each other at the minimum point of
SAC. It lies to the right of A, the minimum point of SMC I.e point B. The relationship
between these two can be summarized as follows:
1. Both AC and MC curve are calculated from the total cost.
2. Both AC and MC are ‘U’ shaped.
3. When AC is falling, the MC curve lies below AC and MC falls faster than AC.
4. When AC is rising, the MC curve lies above the AC and MC rises faster than AC.
5. When AC is minimum, MC=AC
6. MC intersects at the minimum point of AC.
7. MC cuts AC from below.

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UNIT-5
Price and Output Determination under Perfect Completion
Overview
Perfect competition which may define as an ideal market situation in which buyers and sellers
are so numerous and informed that each can act as a price taker, able to buy or sell any
desired quantity affecting the market price.
PERFECT COMPETITION
Perfect Competition which may be defined as an ideal market situation in which buyers and
sellers are so numerous and informed that each can act as a price taker, able to buy or sell any
desired quantity affecting the market price.
According to A.K, Koutsoyianis,"Perfect competition is a market structure characterized by a
complete absence of rivalry among the individual's firms".
ASSUMPTIONS AND FEATURES
It is based on following assumptions and features.
 Large number of buyers and sellers
In perfect competition, there are large number of buyers and sellers in the market. The
individual firm as buyer and seller is simply a price taker.
 Product homogeneity:
Another feature of the perfect competition is the product homogeneity. All products are
perfectly same in terms of size, shape, taste, color, ingredients, quality, trademarks, etc. It
ensures the existence of single price in the market.
 Free entry and exit of the firms:
In the perfect competition, the firms are free to enter or exit in the market. It ensures the
existence of normal profit in perfect competition. When profit is more, new firms enter the
market and this leads to competition.
 No government restrictions:
In perfect competition, there is no government intervention in the form of taxes, subsidies,
licensing policy, control over the supply of raw materials, etc.
Equilibrium of Firm (MR-MC approach)

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Overview
Equilibrium of firm is the situation of a firm to produce a level of output for obtained
maximum profit. It is also called as the difference between Total Revenue (TR) and Total
Cost (TC). The firm gives various outputs sometimes it gives low and sometimes it gives the
high output which provides lower profit to firm. When the situation of nor high nor low i.e.
equilibrium is obtained and it gives more profit.
Equilibrium of Firm (MR-MC approach)
CONCEPT OF MARKET
Generally, market is known as the place where goods and services are purchased and sold.
But, in Economics, market is the contact between the buyer and seller for buying and selling
of the goods at the given price.
EQUILIBRIUM OF FIRM
A firm is said to be in equilibrium when it maximized its profit. It is also called as the
difference between Total Revenue (TR) and Total Cost (TC). The firm gives various outputs;
sometimes it gives low and sometimes it gives the high output which provides lower profit to
firm. When the situation is of not high not low i.e. equilibrium is obtained and it gives more
profit.
Once the firm attained equilibrium, the firm doesn’t have the incentive to change its price and
output because profit is already maximized.
According to Hanson, “A firms will be in equilibrium when it has no advantage to increase or
decrease its output.”
The firm equilibrium is explained with the help of two approaches they are as follows:
1. Marginal Revenue and Marginal Cost approach (MR-MC approach)
2. Total Revenue and Total cost approach (TR-TC approach)
Total revenue and Total cost approach (TR-TC Approach)
According to TR-TC approach, a firm gains equilibrium position at that output at which the
difference between total revenue and the total cost is maximum. Every rational firm aims to
maximize profit.

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π = TR-TC
where; π = profit,
TR = Total Revenue and
TC = Total Cost
A. Equilibrium of a firm under perfect competition:-
Perfect competition is the market structure in which there are a large number of buyers and
sellers selling homogeneous products. A firm is a small part of the whole industry. Price is
fixed by the industry. The firm can sell as much as it wants only at the price fixed by the
industry. The total revenue curve is an upward sloping line which increases at the same rate
in this market. It is generally assumed that Total Cost Curve is inversely ‘S’ shaped. A firm
attains equilibrium at that point at which the difference between TR and TC is maximum. It
can be presented with the help of the following diagram:-
In the above figure, TR and TC represent Total Revenue and Total Cost curves. The
difference between TR and TC is measured by the vertical distance between TR and TC. Up
to OQ1 level of output, the firm bears loss because Total Cost is higher than Total Revenue.
Between OQ1 and OQ3 level of output, the firm is in profit because TR is higher than TC.
The firm earns maximum profit at OQ2 level of output which is shown by the vertical gap
MN. The firm is in equilibrium at OQ2 level of output at point E which is shown in the π
curve (profit curve).
B. Equilibrium of a firm under monopoly:-
Under monopoly, a firm determines the price of its product itself. The monopoly firm
increases its price to increase the revenue or may decrease the price to increase its sales.
Therefore, TR curve is inverse ‘S’ shaped. The firm chooses that level of output at which the

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profit is maximum. The profit is maximized when there is a greater vertical distance between
TR and TC curves. It can be explained by the help of the following diagram:-
In the above figure, TR and TC represent Total Revenue and Total Cost Curve. π curve
represents the profit curve. Before OQ1 and after OQ3 level of output, the firm bears loss
because the total cost is higher than total revenue. From OQ1 to OQ3 level of output, the firm
enjoys profit because TR is higher than TC. The maximum profit is the vertical gap MN
which is also represented in the π curve as Q2E. The firm is equilibrium at this level of output
and does not want to deviate from this point.
Marginal Revenue and Marginal Cost Approach (MR-MC approach)
According to this approach, the firm is said to be in equilibrium if the following conditions
are fulfilled:
1. Marginal cost is equal to Marginal Revenue i.e. ( MC = MR )
2. Marginal cost (MC) Cuts Marginal Revenue (MR) from Below.
3. Marginal cost (MC) Cuts Average Cost (AC) from the Minimum point.
These three conditions are also known as sufficient conditions. If these conditions are
fulfilled the firm is said to be in equilibrium i.e. Maximized profit, which is clearly shown in
the figure below.

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In the above figure, X -axis represents the output and Y -axis represents the Price cost. OP is
the price. Since under the perfect competition AR is equal to MR. AR and MR curves are
horizontal from P. Hence, ‘MR’ Marginal Revenue curve and ‘MC’ Marginal Cost Curve
intersect each other at point E, which is known as Equilibrium point. OQ units of output are
produced in a firm, thus OQ is the Equilibrium Output. So, the profit maximizing output is
OQ. The firm earned supernormal and abnormal profit equal area PABE. If the output is less
than OQ and to obtain the maximum profit, the output should be increased to OQ. The firm
can maximize its profit up to MR is greater than MC i.e.MR > MC. Profit is possible only
until MR is equal to MC i.e. MR = MC. If MC becomes greater than MR then Firm level of
output bear losses.

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Equilibrium of Industry
In Economics, Industry is the group of a firm producing homogeneous product or
commodity. In the perfect competition market the must be fulfilled for an industry to be in
equilibrium they are:
1. Quantity demand equal to Quantity supply i.e. (QD = QS)
2. Marginal cost (MC) Equal to Marginal Revenue (MR) e. (MC = MR) and Marginal
cost (MC) cuts Marginal Revenue (MR) from below.
There should be no tendency on the part of the firm to enter or leave the industry. It is
clearly shown in the figure below:
In the above figure (A), SS is the supply curve and DD is a demand curve and AR and MR is
equal. An industry is in equilibrium at the point “E”. OP is the equilibrium price and OQ is
the equilibrium Quantity output. The industry gets equilibrium at price OP, where demand
and supplies are equal. The firm is in equilibrium by making MC = MR and MC cuts MR
below at the point E. So that it is called firm equilibrium. The firm earned an abnormal profit
equal to area P1EBA. But it should be noticed that if the firm earned supernormal profit or
loss, it is only short-run equilibrium hence, the third condition for equilibrium can be only
realized in a long run.
PRICE AND OUTPUT DETERMINATION UNDER PERFECT COMPETITION

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Industry’s Equilibrium under Perfect Competition
The market price and output is determined on the basis of consumer demand and market
supply under perfect competition. In other words, the firms and industry should be in
equilibrium at a price level in which quantity demand is equal to the quantity supplied. They
make maximum profit if the firm and industry are in equilibrium.
Price of
Curd (Rs.)
Quantity
Demand (Liter)
Quantity
Supplied (Liter)
Conditions
2 90 30
D>S
3 80 40
4 70 50
5 60 60 D=S
6 50 70
D<S
7 40 80
8 30 90
In this above table, we can say that when a price is low, demand is increased. Talking about
the part of supply, as price increases, supply is also increased. When the price is low, the
competition between the consumers can raise the price and when the price is high, the
competition among the sellers reduces the price. So, the price finally comes to be determined
at such a place when the demand and supply of a commodity are equal to each other. At Rs.
5, the demand of curd is 60 liter and supply is also 60 liters.
Fig: Price and output determination under perfect competition market
In the given figure, both the demand curve DD and the supply curve SS are intersected at
point E. So, the point E is the equilibrium point. The price is fixed at OP. At OP, the demand
and supply are equal to OQ. If the price rises from OP to OM, the supply increases. In this

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price, supply exceeds the demand thus at a higher price OM, the quantity MB is supplied but
only the MA quantity is demanded and the quantity AB remains unsold (S>D). Due to this
the price should be reduced and finally the price comes to remain at OP. If price is decreased
form OP to OL than supply decreased up to LT but demand is increased up to LH. Due to
this, there is excess demand than supply. So, the demand exceeds the supply
the consumer starts to compare them to get the quantities of goods they require. As a result,
price again rises to OP.
Short-Run Equilibrium of Firm and Industry
Whether a firm makes abnormal profit or loss depends on the level of AC in the short run
equilibrium. It generally consists of 3 cases i.e. abnormal profit, normal profit, and loss.
According to marginal revenue (MR) and marginal cost (MC) approach firm can get
equilibrium when it mentioned two conditions which are:
 Market demand equal to Market supply.
 Marginal revenue (MR) must be equal to marginal cost (MC) i.e. MC = MR
 MC curve cuts MR curve from below.

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From the figure, the industry demand curve DD and supply curve SS intersect each other at
point 'E' where the market price is P. Firm A enjoys abnormal profit as AC lies below
equilibrium of the AR curve. So, the shaded region PACE is the abnormal profit enjoyed by
the firm. Likewise, firm B faces normal profit, as AC is tangent to AR at equilibrium. Finally,
firm C bears loss and the shaded region PCBE is the loss faced by the firm.
Long-Run Equilibrium of Firm and Industry
A firm, in the long run, can adjust their fixed inputs. In the long run, under perfect
competition, entry and exit are easy and free. All the firms in the perfect competition can earn
only normal profit in the long run.
Under perfect competition, the firms could be in long run equilibrium if they fulfill the
following conditions:
 Long run marginal revenue (LMR) = Long run marginal cost (LMC)
 Long run marginal cost (LMC) must cut long run marginal revenue (LMR) from
below at equilibrium point.
 The slope of LMC must be greater than the slope of LMR.
Fig:
Long run equilibrium of firm and industry
The given figure shows the equillibrium of firm and industry respectively under perfect
competition market. An industry demand curve DD1 and supply curve SS1 intersects each
other at point E where the market price is P. At point E, industry determine OP price for OQ
quantity of product.
Next figure of firm explains long run equilibrium of competitive firm where LMC and LAC
represent long run marginal cost and average cost curves where, at point E, P= LAR = LMR

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= LMC = LAC respectively. OP price is determined for OQ1 level of output and firm making
only normal profit.
Overview
The word monopoly has been derived from two English words ‘mono’ and ‘poly.’ Mono
means single and poly means sellers. Thus monopoly means single seller and large number of
buyers. Consequently, no buyer can influence the price of the product. They sell different
types of commodities or no homogenous products. The monopolists have full right to fix
his/her product price. There is no free entry or exist of firm hence monopolist has full control
over the supply of the product.
Monopoly Market
MEANING OF MONOPOLY MARKET
The word monopoly has been derived from two English words ‘mono’ and ‘poly.’ 'Mono'
means single and 'poly' means sellers. Thus, monopoly means single seller and a large
number of buyers. Consequently, no buyer can influence the price of the product. They sell
different types of commodities or no homogenous products. The monopolists have full right
to fix his/her product price. There is no free entry or exit of firm hence monopolist has full
control over the supply of the product. According to Leftwich, “Monopoly is a market
situation in which single firm sell a product for which there is no clues substitute.”
FEATURESS / ASSUMPTIONS / CHARACTERISTICS OF MONOPOLY MARKET
1. No homogeneous product: - There is no availability of close substitute goods on a
market for competition the product.
2. No free entry or exit of the firm: - The entry and exit of the firm are restricted. Hence,
monopolist has full control over the supply of the product.
3. The firm is price maker: - The monopoly market is the price maker. They adopt their
independent price policy.
4. Price discrimination: - There may be price discrimination in the monopoly market. A
monopolist can sell a product under the different consumer at the different price.
5. Single seller and large number of buyers: The single seller or trader is the main
feature of Monopoly market, which means single trader supply the goods in a market.
So, there is no competition on the market.
PRICE AND OUTPUT DETERMINATIO UNDER MONOPOLY MARKET

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The equilibrium of monopoly firm choosing the profit maximizing and cost minimizing level
of output. It is explained in a short as well as long run context.
SHORT RUN EQUILIBRIUM
The objective of the firm is profit maximization. The price and output are determined under
this situation. There are two approaches to determining the equilibrium output level in short
run i.e. TR and TC approach and MR and MC approach. Here, price and output are
determined only with the help of MR and MC approach.
MR AND MC APPROACH
In the short run, the monopolist firm is in equilibrium when it maximized its profit.
According to MR and MC approach monopolist firm gets equilibrium position when the firm
fulfills the following conditions:-
1. MC=MR
2. MC cuts MR from below
3. MC cuts AC from minimum profit
There are generally three cases
1. Abnormal profit (AR>AC)
2. Normal profit (AR>AV)
3. Loses (AR<AC)
These three cases are clearly explained with the help of figure below:
Figure: Condition of Excess Profit

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Figure: Condition of Normal Profit
Figure: Condition of Loss
In the above figure, we have to draw downward sloping AR (D) and MR curves. At point 'E',
the monopolist is in equilibrium as the two conditions for equilibrium are fulfilled. In the case

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of abnormal profit, AC curve lies below the AR curve at point 'A'. So that, AR is greater than
AC and the region PABC is abnormal profit enjoyed by the firm which is shown in figure i)
super normal profit.
In a case of loss, the AC curve at point 'A’. So that, AR is less than AC and the shaded region
PABC is loss faced by the firm in figure ii) loss.
In a case of normal profit, the AC curve is tangent to AR curve at point 'A'. So that AR is
equal to AC, which is shown in figure iii) normal profit
We can conclude that it is the level of AC that force firm to bear loses or enjoy abnormal
profit or just stay with normal profit at equilibrium. In this way, at equilibrium price 'P', a
firm sells OQ level of output. A firm in monopoly bear loses in rare condition only i.e. at the
time of depression or initial stage of production.
LONG RUN EQUILIBRIUM
A monopolist in a long run always enjoys abnormal profit due to a strong barrier to entry or
exists of the firm. There is enough time for a firm to adjust its factors of production and the
level of output.
In the above figure, AR and MR are flatter than the short run AR and MR But price is less
than that of the short run. The equilibrium, in the long run, is attained at point 'E' where
equilibrium condition is fulfilled. The equilibrium price is OP and output is OQ. Here,
average cost QB is greater than average revenue by AB. In this condition LAC, a curve is
below AR curve at point A. So, A monopolists enjoy abnormal profit shown by the region i.e.
PABC.