Costs of Production

Costs of

Production

Costs of

Production

The Meaning of CostsThe Meaning of Costs

• Opportunity costs– meaning of opportunity cost

– examples

• Measuring a firm’s opportunity costs– factors not owned by the firm: explicit costs

– factors already owned by the firm: implicit costs

– irrelevance of:• historic costs

• replacement costs

• Opportunity costs– meaning of opportunity cost

– examples

• Measuring a firm’s opportunity costs– factors not owned by the firm: explicit costs

– factors already owned by the firm: implicit costs

– irrelevance of:• historic costs

• replacement costs

Production in the Short runProduction in the Short run

• Production functions

– factors of production

• labour

• land and raw materials

• capital

• entrepreneurship

– the relationship between inputs and output

• TPP = ƒ(F1, F2, F3, … Fn)

• Production functions

– factors of production

• labour

• land and raw materials

• capital

• entrepreneurship

– the relationship between inputs and output

• TPP = ƒ(F1, F2, F3, … Fn)

Production in the Short runProduction in the Short run

• Long-run and short-run production – fixed and variable factors

– distinction between short run and long run

• The law of diminishing returns

• The short-run production function:– total physical product (TPP)

– average physical product (APP)

– marginal physical product (MPP)

– the graphical relationship between TPP, APP and MPP

• Long-run and short-run production – fixed and variable factors

– distinction between short run and long run

• The law of diminishing returns

• The short-run production function:– total physical product (TPP)

– average physical product (APP)

– marginal physical product (MPP)

– the graphical relationship between TPP, APP and MPP

0

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Number of farm workers

Wheat production per year from a particular farmWheat production per year from a particular farmT

onn

es

of w

he

at p

rod

uce

d p

er

yea

r

Number of workers

012345678

TPP 0 310243640424240

0

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To

nne

s o

f wh

eat

pro

du

ced

pe

r ye

ar

Number of workers

012345678

TPP 0 310243640424240

Wheat production per year from a particular farmWheat production per year from a particular farm

0

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To

nne

s o

f wh

eat

pro

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ced

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ar TPP

b

Diminishing returnsset in here

d

Maximum output

-2

0

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Number offarm workers (L)

Ton

nes

of w

heat

per

yea

r

TPP

Ton

nes

of w

heat

per

yea

r


TPP = 7

L = 1

MPP = TPP / L = 7


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-2

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Ton

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of w

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TPP

Ton

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yea

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MPP




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-2

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Ton

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of w

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TPP

Ton

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of w

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yea

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APP

MPP

APP = TPP / L




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-2

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b

b

Ton

nes

of w

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r

TPP

Ton

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of w

heat

per

yea

r

APP

MPP

Diminishing returnsset in here




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-2

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Ton

nes

of w

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TPP

Ton

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of w

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per

yea

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APP

MPP

b

d

d



Maximumoutput

b


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c

c

-2

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Ton

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TPP

Ton

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APP

MPP

b

b

d

d



Slope = TPP / L= APP


Costs in the Short runCosts in the Short run

• Costs and inputs

– costs and the productivity of factors

– costs and the price of factors

• Fixed costs and variable costs

• Total costs

– total fixed cost (TFC)

– total variable cost (TVC)

• TVC and the law of diminishing returns

– total cost (TC = TFC + TVC)

• Costs and inputs

– costs and the productivity of factors

– costs and the price of factors

• Fixed costs and variable costs

• Total costs

– total fixed cost (TFC)

– total variable cost (TVC)

• TVC and the law of diminishing returns

– total cost (TC = TFC + TVC)

0

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Output(Q)

01234567

TFC(£)

1212121212121212

Total costs for firm XTotal costs for firm X

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TFC

Output(Q)

01234567

TFC(£)

1212121212121212


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TFC

Total costs for firm XTotal costs for firm XOutput

(Q)

01234567

TFC(£)

1212121212121212

TVC(£)

010162128406091

0

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0 1 2 3 4 5 6 7 8

TVC

Output(Q)

01234567

TFC(£)

1212121212121212

TVC(£)

010162128406091

TFC


0

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40

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0 1 2 3 4 5 6 7 8

TVC

TFC

Total costs for firm XTotal costs for firm XOutput

(Q)

01234567

TFC(£)

1212121212121212

TVC(£)

010162128406091

TC(£)

12222833405272

103

0

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0 1 2 3 4 5 6 7 8

TCOutput

(Q)

01234567

TFC(£)

1212121212121212

TVC(£)

010162128406091

TC(£)

12222833405272

103

TVC

TFC


0

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TC

TVC

TFC


Diminishing marginalreturns set in here


• Marginal cost

– marginal cost (MC) and the law of diminishing returns

• Marginal cost


Output (Q)

Co

sts

(£)

MC

x

Average and marginal costsAverage and marginal costs

Diminishing marginalreturns set in here


• Marginal cost


– the relationship between MC and TC curves

• Marginal cost


– the relationship between MC and TC curves

Output (Q)

Co

sts

(£)

MC

x



• Average cost

– average fixed cost (AFC)

– average variable cost (AVC)

– average (total) cost (AC)

• Relationship between average and marginal cost

• Average cost

– average fixed cost (AFC)

– average variable cost (AVC)

– average (total) cost (AC)

• Relationship between average and marginal cost

Output (Q)

Co

sts

(£)

AFC

AVC

MC

x

AC

z

y


Production in the Long runProduction in the Long run

• All factors variable in long run

• The scale of production:

– constant returns to scale

– increasing returns to scale





Short-run and long-run increases in outputShort-run and long-run increases in output









– decreasing returns to scale












• Returns to scale and economies and diseconomies of scale






• Returns to scale and economies and diseconomies of scale


• Economies of scale– specialisation & division of labour

– indivisibilities

– container principle

– greater efficiency of large machines

– by-products

– multi-stage production

– organisational & administrative economies

– financial economies

• Economies of scope

• Economies of scale– specialisation & division of labour

– indivisibilities

– container principle

– greater efficiency of large machines

– by-products

– multi-stage production

– organisational & administrative economies

– financial economies

• Economies of scope


• Diseconomies of scale– managerial diseconomies

– effects of workers and industrial relations

– risks of interdependencies

• External economies of scale

• External diseconomies of scale

• Location– balancing the distance from suppliers and

consumers

– importance of transport costs

• Diseconomies of scale– managerial diseconomies

– effects of workers and industrial relations

– risks of interdependencies

• External economies of scale

• External diseconomies of scale

• Location– balancing the distance from suppliers and

consumers

– importance of transport costs


• Optimum combination of factors

– MPPa/Pa = MPPb/Pb ... = MPPn/Pn

• Decision making in different time periods– very short run

– short run

– long run

– very long run

– decisions can be made for all time periods at the same time

• Optimum combination of factors

– MPPa/Pa = MPPb/Pb ... = MPPn/Pn

• Decision making in different time periods– very short run

– short run

– long run

– very long run

– decisions can be made for all time periods at the same time

Costs in the Long runCosts in the Long run

• Long-run average costs– shape of the LRAC curve

– assumptions behind the curve



Alternative long-run average cost curvesAlternative long-run average cost curves

OutputO

Co

sts

LRAC

Economies of Scale

OutputO

Co

sts

LRAC


Diseconomies of Scale

OutputO

Co

sts

LRAC


Constant costs

A typical long-run average cost curveA typical long-run average cost curve

OutputO

Co

sts

LRAC

A typical long-run average cost curveA typical long-run average cost curve

OutputO

Co

sts

LRACEconomiesof scale

Constantcosts

Diseconomiesof scale


• Long-run average costs

– shape of the LRAC curve


• Long-run marginal costs

• Long-run average costs

– shape of the LRAC curve



Long-run average and marginal costsLong-run average and marginal costs

OutputO

Co

sts

LRAC

LRMC

Economies of Scale

OutputO

Co

sts

LRAC


LRMC

Diseconomies of Scale

OutputO

Co

sts

LRAC


= LRMC

Constant costs

OutputO

Co

sts


LRMC

LRAC

Initial economies of scale,then diseconomies of scale





• Relationship between long-run and short-run average costs




• Relationship between long-run and short-run average costs





• Relationship between long-run and short-run average costs– the envelope curve





Deriving long-run average cost curves: factories of fixed sizeDeriving long-run average cost curves: factories of fixed size

SRAC3

Co

sts

OutputO

SRAC4

SRAC5

5 factories

4 factories3 factories2 factories

1 factory

SRAC1 SRAC2

SRAC1

SRAC3

SRAC2 SRAC4

SRAC5

LRAC

Co

sts

OutputO

Deriving long-run average cost curves: factories of fixed sizeDeriving long-run average cost curves: factories of fixed size

Deriving a long-run average cost curve: choice of factory sizeDeriving a long-run average cost curve: choice of factory sizeC

ost

s

OutputO

Examples of short-runaverage cost curves

LRAC

Co

sts

OutputO

Deriving a long-run average cost curve: choice of factory sizeDeriving a long-run average cost curve: choice of factory size






• Long-run cost curves in practice





• Long-run cost curves in practice






• Long-run cost curves in practice– the evidence












– minimum efficient plant size






– minimum efficient plant size

Costs of Production

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