SHORT-RUN THEORY OF PRODUCTION Profits and the aims of the firm Long-run and short-run production:...

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SHORT-RUN THEORY OF PRODUCTIONSHORT-RUN THEORY OF PRODUCTION

• Profits and the aims of the firm

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

• 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

• Profits and the aims of the firm

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

• 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

Wheat production per year from a particular farm (tonnes)Wheat production per year from a particular farm (tonnes)

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

Number of farm workers

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TPP 0 310243640424240

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

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Number of farm workers

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

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Number of farm workers

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Diminishing returnsset in here

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

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Maximum output

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

Number offarm workers (L)

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TPP = 7

L = 1

MPP = TPP / L = 7

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

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nes

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TPP

-2

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of w

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MPP

Number offarm workers (L)

Number offarm workers (L)

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

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nes

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TPP

-2

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APP

MPP

APP = TPP / L

Number offarm workers (L)

Number offarm workers (L)

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

Ton

nes

of w

heat

per

yea

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TPP

-2

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0 1 2 3 4 5 6 7 8

Ton

nes

of w

heat

per

yea

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APP

MPP

b

Diminishing returnsset in here

Number offarm workers (L)

Number offarm workers (L)

b

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0 1 2 3 4 5 6 7 8

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

Ton

nes

of w

heat

per

yea

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TPP

-2

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0 1 2 3 4 5 6 7 8

Ton

nes

of w

heat

per

yea

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APP

MPP

b

d

d

Number offarm workers (L)

Number offarm workers (L)

Maximumoutputb

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

Ton

nes

of w

heat

per

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TPP

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Ton

nes

of w

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per

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APP

MPP

b

b

d

d

Number offarm workers (L)

Number offarm workers (L)

Slope = TPP / L= APP

c

c

LONG-RUN THEORY OF PRODUCTIONLONG-RUN THEORY OF PRODUCTION

• All factors variable in long run

• The scale of production:

– constant returns to scale

– increasing returns to scale

– decreasing returns to scale

• All factors variable in long run

• The scale of production:

– constant returns to scale

– increasing returns to scale

– decreasing returns to scale

LONG-RUN THEORY OF PRODUCTIONLONG-RUN THEORY OF PRODUCTION

• 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

LONG-RUN THEORY OF PRODUCTIONLONG-RUN THEORY OF PRODUCTION

• Diseconomies of scale

• External economies and diseconomies of scale

• Optimum combination of factorsMPPa/Pa = MPPb/Pb ... = MPPn/Pn

• Diseconomies of scale

• External economies and diseconomies of scale

• Optimum combination of factorsMPPa/Pa = MPPb/Pb ... = MPPn/Pn

ISOQUANT- ISOCOST ANALYSISISOQUANT- ISOCOST ANALYSIS

• Isoquants

– their shape

– diminishing marginal rate of substitution

– isoquants and returns to scale

– isoquants and marginal returns

• Isocosts

– slope and position of the isocost

– shifts in the isocost

• Isoquants

– their shape

– diminishing marginal rate of substitution

– isoquants and returns to scale

– isoquants and marginal returns

• Isocosts

– slope and position of the isocost

– shifts in the isocost

Unitsof K402010 6 4

Unitsof L 512203050

Point ondiagram

abcde

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Units of labour (L)

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An isoquantAn isoquant

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its o

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Units of labour (L)

g

hK = 2

L = 1

isoquant

MRS = 2 MRS = K / L

Diminishing marginal rate of factor substitutionDiminishing marginal rate of factor substitution

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g

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k

K = 2

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K = 1

L = 1

Diminishing marginal rate of factor substitutionDiminishing marginal rate of factor substitution

isoquant

MRS = 2

MRS = 1

MRS = K / L

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An isoquant mapAn isoquant mapU

nits

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ap

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K)

Units of labour (L)

I1

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I2

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Units of labour (L)

An isoquant mapAn isoquant map

I1

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I2

I3

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Units of labour (L)

An isoquant mapAn isoquant map

I1

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I2

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I4

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Units of labour (L)

An isoquant mapAn isoquant map

I1

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I1I2

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Units of labour (L)

An isoquant mapAn isoquant map

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An isocostAn isocost

Units of labour (L)

Un

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)

Assumptions

PK = £20 000 W = £10 000

TC = £300 000

TC = £300 000

a

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Units of labour (L)

Un

its o

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TC = £300 000

a

b

Assumptions

PK = £20 000 W = £10 000

TC = £300 000

An isocostAn isocost

0

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0 5 10 15 20 25 30 35 40

Units of labour (L)

Un

its o

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pita

l (K

)

TC = £300 000

a

b

c

Assumptions

PK = £20 000 W = £10 000

TC = £300 000

An isocostAn isocost

0

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0 5 10 15 20 25 30 35 40

Units of labour (L)

Un

its o

f ca

pita

l (K

)

TC = £300 000

a

b

c

d

Assumptions

PK = £20 000 W = £10 000

TC = £300 000

An isocostAn isocost

ISOQUANT- ISOCOST ANALYSISISOQUANT- ISOCOST ANALYSIS

• Least-cost combination of factors for a given output

– point of tangency

– comparison with marginal productivity approach

• Highest output for a given cost of production

• Least-cost combination of factors for a given output

– point of tangency

– comparison with marginal productivity approach

• Highest output for a given cost of production

0

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0 10 20 30 40 50

Finding the least-cost method of productionFinding the least-cost method of production

Units of labour (L)

Un

its o

f ca

pita

l (K

)

Assumptions

PK = £20 000W = £10 000

TC = £200 000

TC = £300 000

TC = £400 000

TC = £500 000

0

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Units of labour (L)

Un

its o

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pita

l (K

)Finding the least-cost method of productionFinding the least-cost method of production

TPP1

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Units of labour (L)

Un

its o

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pita

l (K

)Finding the least-cost method of productionFinding the least-cost method of production

TC = £400 000r

TPP1

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0 10 20 30 40 50

Units of labour (L)

Un

its o

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pita

l (K

)Finding the least-cost method of productionFinding the least-cost method of production

TC = £400 000

TC = £500 000s

r

tTPP1

Finding the maximum output for a given total costFinding the maximum output for a given total cost

TPP1TPP2

TPP3

TPP4

TPP5

Un

its o

f ca

pita

l (K

)

Units of labour (L)

O

O

Isocost

Un

its o

f ca

pita

l (K

)

Units of labour (L)

TPP1TPP2

TPP3

TPP4

TPP5

Finding the maximum output for a given total costFinding the maximum output for a given total cost

O

r

v

Un

its o

f ca

pita

l (K

)

Units of labour (L)

TPP1TPP2

TPP3

TPP4

TPP5

Finding the maximum output for a given total costFinding the maximum output for a given total cost

O

s

u

Un

its o

f ca

pita

l (K

)

Units of labour (L)

TPP1TPP2

TPP3

TPP4

TPP5

r

v

Finding the maximum output for a given total costFinding the maximum output for a given total cost

O

t

Un

its o

f ca

pita

l (K

)

Units of labour (L)

TPP1TPP2

TPP3

TPP4

TPP5

r

v

s

u

Finding the maximum output for a given total costFinding the maximum output for a given total cost

O

K1

L1

Un

its o

f ca

pita

l (K

)

Units of labour (L)

TPP1TPP2

TPP3

TPP4

TPP5

r

v

s

u

t

Finding the maximum output for a given total costFinding the maximum output for a given total cost

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