8/7/2019 p&rchapter_6[1] http://slidepdf.com/reader/full/prchapter61 1/39 Theory of Firm Production
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Theory of FirmProduction
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Chapter 6 Slide 2
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Slide 3
Lecture Plan, theory of firm
1.Production function
2.
3.Cost of production
4.
5.Revenue and Profit
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The Technology of Production
n Production Function:l Indicates the highest output that a firm
can produce for every specifiedcombination of inputs given the stateof technology.
l Shows what is technically feasible when
the firm operates efficiently .
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The Technology of Production
n The Production Processl Combining inputs or factors of
production to achieve an output or desired level
n Categories of Inputs (factors of production)
l Labor l Materials/rawl Capital
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Firm’s Costs and Production Decision
n A firm chooses:l What quantity of the good to produce,l The price of the good (sometimes...).
n Firm’s decision depends on:l Costs of production.l
The degree of competition in the market(if there are more sellers, morecompetitive).
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Role of a Firm
n The firm is an economic institution thattransforms factors of production intoconsumer goods – it:
l Organizes factors of production.l Produces goods and services.l Sells produced goods and services.
l Objective is to Maximize profit
ProfitProfit = Total= Total RR evenue - Totalevenue - Total CC ostost
l
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The Production Process
A firm chooses from all
possible productiontechniquesAll inputs are variable
The production process can be divided into the long runand the short run, depends on availability of inputs.
The terms long run and short run do not necessarily refer tospecific periods of time, but to the flexibility the firm has inchanging the level of output
Short run Long runA firm is constrained in regard
to what productiondecisions it can makeSome inputs are fixed
1
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nRailways – short run –’easy’ to increaselabour, long lead timesfor new rolling stock – 5 years?
n Supermarkets – short run – can buy new
shelving, hire staff, etc but opening of newstores takes several yearsn Local Builder – short run buys new tools,
hires assistant; long run – purchasing a new
van – a coupleof months?
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The Technology of Production
n The production function for one input:Q = F(L)| all other inputs are fixed
nThe production function for two inputs:
Q = F(K,L)
Q = Output , K = Capital, L = Labor
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Slide 11
Production function with one input
Q = F(L)| all other inputs are fixedProduction depends upon labor only.
It’s a Short Run Process
Subject to Law of diminishing MarginalProduct:
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Law of Diminishing Marginalproductivity
Number of workers Total output Marginalproduct Averageproduct
Increasing marginalreturns
Diminishingmarginal returns
Diminishingabsolute returns
4
6765310
25
1234
5
67
89
10
045
5.75.85.6
5.24.6
4.03.32.5
—4
10
172328
3132
323025
0
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Outp ut
Diminishi ng marginal
returns
Diminishi ng absolute
returns 32 30 28 26 24
22 20 18 16 14 12 10 8
6 4 2
01 2 3 4 5 6 7 8 9 10
Increasi ng marginal
returns
Number of workers
TP
Outp ut
p er
worker
1 2 3 4 5 6 7 8 9 10 Number of workers
7
6
5
4
3
2
1
0
MP
Diminishi ng marginal
returns
Diminishi ng absolute
returns
( )a Total product ( )b Marginal and average product
AP
The Law of Diminishing Marginal Productivity
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Graphing a ProductionFunction
Q
Increasingmarginal
productivity
Diminishingmarginal
productivity
DiminishingAbsolute
productivity
Number of
workers
TPA production function is the relationship between
32
26
20
14
821 2 3 4 5 6 7 8
9 10
12-14
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Graphing Marginal andAverage Productivity
Increasingmarginal
productivity
Diminishingmarginal
productivity
DiminishingAbsolute
productivity
Number of workers
AP
MP
QMarginal productivity first increThen m arginal productivity declEventually marginal productivity is
8
6
4
2
0
-2
-4-6
1 2 3 4 5 6 7 89 10
12-15
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Law of Diminishing Marginal Productivity # of workers
TotalOutput
MarginalProduct
AverageProduct0 0 4
6765
310-2-5
---1 4 42 10 53 17 5.74 23 5.8
5 28 5.66 31 5.27 32 4.68 32 4.0
9 30 3.310 25 2.5
Law of diminishingmarginal productivity
states as more of avariable input is added to
an existing fixed input,after some point the
additional output from theadditional input will fall
Increasingmarginal
productivity
Diminishingmarginal
productivity
DiminishingAbsolute
productivity 12-16
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Slide 17
n When the labor input is small, MP increases dueto specialization.
n When the labor input is large, MP decreases dueto inefficiencies.
n Can be used for long-run decisions to evaluatethe trade-offs of different plant configurations
n Assumes the quality of the variable input isconstant
n
The Law of Diminishing Marginal ReturnsThe Law of Diminishing Marginal Returns
Production withOne Variable Input (Labor)
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Slide 19
Role of Engineers !!!!!
How could we enhance the productionand profit if we have one input factor?
h ff f
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Slide 20
The Effect of Technological Improvement
Labor per time period
Outputper time
period
50
100
0 2 3 4 5 6 7 8 9 101
A
O 1
C
O 3
O 2
B
Labor productivitycan increase if thereare improvements in
technology, even thoughany given production
process exhibitsdiminishing returns to
labor.
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Slide 21
Production with two variables
Examples:l Cobb-Douglas Production Functionl Linear Production Function
l Leontief production functionl The Constant Elasticity of Substitution
(CES) Production Function
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Slide 22
Production Function: for Food ( Q=F(l,K)
1 20 40 55 65 75
2 40 60 75 85 90
3 55 75 90 100 105
4 65 85 100 110 1155 75 90 105 115 120
Capital Input 1 2 3 4 5Labor Input
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Slide 23
Isoquants
n Isoquantsl In Latin, "iso" means equal and "quant"
refers to quantity. This translates to"equal quantity". The isoquant curvehelps firms to adjust their inputs tomaximize output and profits.
l Curves showing all possible combinationsof inputs that yield the same output
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Slide 24
Production with Two Variable Inputs ( L,K )
Labor per year
1
2
3
4
1 2 3 4 5
5
Q 1 = 55
The isoquants are derivedfrom the production
function for output of of 55, 75, and 90.A
D
B
Q 2 = 75Q 3 = 90
C
E Capitalper year The Isoquant MapThe Isoquant Map
P d i i h
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Slide 25
Production withTwo Variable Inputs
n Long-run production K& L are variable.
n Isoquants analyze and compare thedifferent combinations of K & L andoutput
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Slide 26
The Shape of Isoquants
Labor per year
1
2
3
4
1 2 3 4 5
5
In the long run bothlabor and capital are
variable and bothexperience diminishing
returns.
Q 1 = 55
Q 2 = 75Q 3 = 90
Capitalper year
A
D
B C
E
P d ti ith
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Slide 27
n Substituting Among Inputsl The slope of each isoquant gives the
trade-off between two inputs whilekeeping output constant.
Production withTwo Variable Inputs
P d ti ith
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Slide 28
n Substituting Among Inputsl The marginal rate of technical substitution
equals:
inputlabor inangecapital/ChinChange - MRTS =
LK MRTS ∆∆−=
Production withTwo Variable Inputs
M i l R f
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Slide 29
Marginal Rate of Technical Substitution
Labor per month
1
2
3
4
1 2 3 4 5
5Capitalper year
Isoquants are downwardsloping and convex
like indifferencecurves.
1
1
1
1
2
1
2/31/3
Q 1 =55
Q 2 =75
Q 3
=90
P d ti ith
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Slide 30
u If output is constant and labor isincreased, then:
0 K))( (MP L))( (MP K L =∆+∆MRTS L)K/ ( - ))/(MP (MP K L =∆∆=
Production withTwo Variable Inputs
I t Wh I t
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Slide 31
Isoquants When Inputs arePerfectly Substitutable
Labor per month
Capitalper
month
Q 1 Q 2 Q 3
A
B
C
Fi d P i
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Slide 32
Fixed-ProportionsProduction Function
Labor per month
Capitalper
month
L1
K 1 Q 1
Q 2
Q 3
A
B
C
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Slide 33
A Production Function for Wheat
n Farmers must choose between a capitalintensive or labor intensive techniqueof production.
I t D ibi th
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Slide 34
Isoquant Describing theProduction of Wheat
Labor (hours per year)
Capital(machinehour per
year)
250 500 760 1000
40
80
120
10090
Output = 13,800 bushelsper year
AB
10- K =∆
260 L =∆
Point A is morecapital-intensive, and
B is more labor-intensive.
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Slide 35
Returns to Scale
n Measuring the relationship between thescale (size) of a firm and output
1) Increasing returns to scale :output more than doubles when allinputs are doubled
u Larger output associated with lower cost
(autos)u One firm is more efficient than many
(utilities)u The isoquants get closer together
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Slide 36
Returns to Scale
Labor (hours)
Capital(machine
hours)
10
20
30
Increasing Returns:The isoquants move closer together
5 10
2
4
0
A
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Slide 37
Returns to Scale
n Measuring the relationship between thescale (size) of a firm and output
2) Constant returns to scale :output doubles when all inputs aredoubled
u Size does not affect productivityu May have a large number of
producersu Isoquants are equidistant apart
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Slide 38
Returns to Scale
Labor (hours)
Capital(machine
hours)
Constant Returns:Isoquants are
equallyspaced
10
20
30
155 10
2
4
0
A
6
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Returns to Scale
n Measuring the relationship between thescale (size) of a firm and output
3) Decreasing returns to scale :output less than doubles when allinputs are doubled
u Decreasing efficiency with largesize
u Reduction of entrepreneurialabilities