Title: Chapter Thirty-Two
1Chapter Thirty-Two
2Exchange Economies (revisited)
- No production, only endowments, so no description
of how resources are converted to consumables. - General equilibrium all markets clear
simultaneously. - 1st and 2nd Fundamental Theorems of Welfare
Economics.
3Now Add Production ...
- Add input markets, output markets, describe
firms technologies, the distributions of firms
outputs and profits
4Now Add Production ...
- Add input markets, output markets, describe
firms technologies, the distributions of firms
outputs and profits Thats not easy!
5Robinson Crusoes Economy
- One agent, RC.
- Endowed with a fixed quantity of one resource --
24 hours. - Use time for labor (production) or leisure
(consumption). - Labor time L. Leisure time 24 - L.
- What will RC choose?
6Robinson Crusoes Technology
- Technology Labor produces output (coconuts)
according to a concave production function.
7Robinson Crusoes Technology
Coconuts
Production function
24
0
Labor (hours)
8Robinson Crusoes Technology
Coconuts
Production function
Feasible productionplans
24
0
Labor (hours)
9Robinson Crusoes Preferences
- RCs preferences
- coconut is a good
- leisure is a good
10Robinson Crusoes Preferences
Coconuts
More preferred
24
0
Leisure (hours)
11Robinson Crusoes Preferences
Coconuts
More preferred
Leisure (hours)
24
0
12Robinson Crusoes Choice
Coconuts
Production function
Feasible productionplans
24
0
Labor (hours)
13Robinson Crusoes Choice
Coconuts
Production function
Feasible productionplans
24
0
Labor (hours)
Leisure (hours)
24
0
14Robinson Crusoes Choice
Coconuts
Production function
Feasible productionplans
24
0
Labor (hours)
Leisure (hours)
24
0
15Robinson Crusoes Choice
Coconuts
Production function
Feasible productionplans
24
0
Labor (hours)
Leisure (hours)
24
0
16Robinson Crusoes Choice
Coconuts
Production function
C
24
L
0
Labor (hours)
Leisure (hours)
24
0
17Robinson Crusoes Choice
Coconuts
Production function
C
Labor
24
L
0
Labor (hours)
Leisure (hours)
24
0
18Robinson Crusoes Choice
Coconuts
Production function
C
Labor
Leisure
24
L
0
Labor (hours)
Leisure (hours)
24
0
19Robinson Crusoes Choice
Coconuts
Production function
C
Output
Labor
Leisure
24
L
0
Labor (hours)
Leisure (hours)
24
0
20Robinson Crusoes Choice
Coconuts
MRS MPL
Production function
C
Output
Labor
Leisure
24
L
0
Labor (hours)
Leisure (hours)
24
0
21Robinson Crusoe as a Firm
- Now suppose RC is both a utility-maximizing
consumer and a profit-maximizing firm. - Use coconuts as the numeraire good i.e. price of
a coconut 1. - RCs wage rate is w.
- Coconut output level is C.
22Robinson Crusoe as a Firm
- RCs firms profit is ? C - wL.
- ? C - wL ? C ? wL, the equation of an
isoprofit line. - Slope w .
- Intercept ? .
23Isoprofit Lines
Coconuts
Higher profit
Slopes w
24
0
Labor (hours)
24Profit-Maximization
Coconuts
Production function
Feasible productionplans
24
0
Labor (hours)
25Profit-Maximization
Coconuts
Production function
24
0
Labor (hours)
26Profit-Maximization
Coconuts
Production function
24
0
Labor (hours)
27Profit-Maximization
Coconuts
Production function
C
24
L
0
Labor (hours)
28Profit-Maximization
Isoprofit slope production function slope
Coconuts
Production function
C
24
L
0
Labor (hours)
29Profit-Maximization
Isoprofit slope production function slope
i.e. w MPL
Coconuts
Production function
C
24
L
0
Labor (hours)
30Profit-Maximization
Isoprofit slope production function slope
i.e. w MPL 1? MPL MRPL.
Coconuts
Production function
C
24
L
0
Labor (hours)
31Profit-Maximization
Isoprofit slope production function slope
i.e. w MPL 1? MPL MRPL.
Coconuts
Production function
C
24
L
0
Labor (hours)
RC gets
32Profit-Maximization
Isoprofit slope production function slope
i.e. w MPL 1? MPL MRPL.
Coconuts
Production function
C
Given w, RCs firms quantity demanded of labor
is L
Labor demand
24
L
0
Labor (hours)
RC gets
33Profit-Maximization
Isoprofit slope production function slope
i.e. w MPL 1? MPL MRPL.
Coconuts
Production function
C
Output supply
Given w, RCs firms quantity demanded of labor
is L and output quantity supplied is C.
Labor demand
24
L
0
Labor (hours)
RC gets
34Utility-Maximization
- Now consider RC as a consumer endowed with ?
who can work for w per hour. - What is RCs most preferred consumption bundle?
- Budget constraint is
35Utility-Maximization
Coconuts
Budget constraint
24
0
Labor (hours)
36Utility-Maximization
Coconuts
Budget constraint slope w
24
0
Labor (hours)
37Utility-Maximization
Coconuts
More preferred
24
0
Labor (hours)
38Utility-Maximization
Coconuts
Budget constraint slope w
24
0
Labor (hours)
39Utility-Maximization
Coconuts
Budget constraint slope w
24
0
Labor (hours)
40Utility-Maximization
Coconuts
Budget constraint slope w
C
24
L
0
Labor (hours)
41Utility-Maximization
Coconuts
MRS w
Budget constraint slope w
C
24
L
0
Labor (hours)
42Utility-Maximization
Coconuts
MRS w
Budget constraint slope w
C
Given w, RCs quantity supplied of labor is L
Labor supply
24
L
0
Labor (hours)
43Utility-Maximization
Coconuts
MRS w
Budget constraint slope w
C
Output demand
Given w, RCs quantity supplied of labor is L
and output quantity demanded is C.
Labor supply
24
L
0
Labor (hours)
44Utility-Maximization Profit-Maximization
- Profit-maximization
- w MPL
- quantity of output supplied C
- quantity of labor demanded L
45Utility-Maximization Profit-Maximization
- Profit-maximization
- w MPL
- quantity of output supplied C
- quantity of labor demanded L
- Utility-maximization
- w MRS
- quantity of output demanded C
- quantity of labor supplied L
46Utility-Maximization Profit-Maximization
- Profit-maximization
- w MPL
- quantity of output supplied C
- quantity of labor demanded L
- Utility-maximization
- w MRS
- quantity of output demanded C
- quantity of labor supplied L
Coconut and labor markets both clear.
47Utility-Maximization Profit-Maximization
Coconuts
MRS w MPL
Given w, RCs quantity supplied of labor
quantity demanded of labor L and output
quantity demanded output quantity supplied C.
C
24
L
0
Labor (hours)
48Pareto Efficiency
49Pareto Efficiency
Coconuts
MRS ? MPL
24
0
Labor (hours)
50Pareto Efficiency
Coconuts
MRS ? MPL
Preferred consumption bundles.
24
0
Labor (hours)
51Pareto Efficiency
Coconuts
MRS MPL
24
0
Labor (hours)
52Pareto Efficiency
Coconuts
MRS MPL. The common slope ? relative
wage rate w that implements
the Pareto
efficient plan by
decentralized pricing.
24
0
Labor (hours)
53First Fundamental Theorem of Welfare Economics
- A competitive market equilibrium is Pareto
efficient if - consumers preferences are convex
- there are no externalities in consumption or
production.
54Second Fundamental Theorem of Welfare Economics
- Any Pareto efficient economic state can be
achieved as a competitive market equilibrium if - consumers preferences are convex
- firms technologies are convex
- there are no externalities in consumption or
production.
55Non-Convex Technologies
- Do the Welfare Theorems hold if firms have
non-convex technologies?
56Non-Convex Technologies
- Do the Welfare Theorems hold if firms have
non-convex technologies? - The 1st Theorem does not rely upon firms
technologies being convex.
57Non-Convex Technologies
Coconuts
MRS MPL The common slope ? relative
wage rate w that
implements the Pareto
efficient plan by
decentralized pricing.
24
0
Labor (hours)
58Non-Convex Technologies
- Do the Welfare Theorems hold if firms have
non-convex technologies? - The 2nd Theorem does require that firms
technologies be convex.
59Non-Convex Technologies
Coconuts
MRS MPL. The Pareto optimal allocation
cannot be implemented by
a competitive
equilibrium.
24
0
Labor (hours)
60Production Possibilities
- Resource and technological limitations restrict
what an economy can produce. - The set of all feasible output bundles is the
economys production possibility set. - The sets outer boundary is the production
possibility frontier.
61Production Possibilities
Coconuts
Production possibility frontier (ppf)
Fish
62Production Possibilities
Coconuts
Production possibility frontier (ppf)
Production possibility set
Fish
63Production Possibilities
Coconuts
Feasible but inefficient
Fish
64Production Possibilities
Coconuts
Feasible and efficient
Feasible but inefficient
Fish
65Production Possibilities
Coconuts
Feasible and efficient
Infeasible
Feasible but inefficient
Fish
66Production Possibilities
Coconuts
Ppfs slope is the marginal rate of product
transformation.
Fish
67Production Possibilities
Coconuts
Ppfs slope is the marginal rate of product
transformation.
Increasingly negative MRPT ? increasing
opportunity cost to specialization.
Fish
68Production Possibilities
- If there are no production externalities then a
ppf will be concave w.r.t. the origin. - Why?
69Production Possibilities
- If there are no production externalities then a
ppf will be concave w.r.t. the origin. - Why?
- Because efficient production requires
exploitation of comparative advantages.
70Comparative Advantage
- Two agents, RC and Man Friday (MF).
- RC can produce at most 20 coconuts or 30 fish.
- MF can produce at most 50 coconuts or 25 fish.
71Comparative Advantage
C
RC
20
30
F
C
MF
50
25
F
72Comparative Advantage
C
RC
MRPT -2/3 coconuts/fish so opp. cost of
one more fish is 2/3 foregone coconuts.
20
30
F
C
MF
50
25
F
73Comparative Advantage
C
RC
MRPT -2/3 coconuts/fish so opp. cost of
one more fish is 2/3 foregone coconuts.
20
30
F
C
MF
50
MRPT -2 coconuts/fish so opp. cost of one more
fish is 2 foregone coconuts.
25
F
74Comparative Advantage
C
RC
MRPT -2/3 coconuts/fish so opp. cost of
one more fish is 2/3 foregone coconuts.
20
RC has the comparative opp. cost advantage
in producing fish.
30
F
C
MF
50
MRPT -2 coconuts/fish so opp. cost of one more
fish is 2 foregone coconuts.
25
F
75Comparative Advantage
C
RC
MRPT -2/3 coconuts/fish so opp. cost of
one more coconut is 3/2 foregone fish.
20
30
F
C
MF
50
25
F
76Comparative Advantage
C
RC
MRPT -2/3 coconuts/fish so opp. cost of
one more coconut is 3/2 foregone fish.
20
30
F
C
MF
50
MRPT -2 coconuts/fish so opp. cost of one more
coconut is 1/2 foregone fish.
25
F
77Comparative Advantage
C
RC
MRPT -2/3 coconuts/fish so opp. cost of
one more coconut is 3/2 foregone fish.
20
30
F
C
MF
50
MRPT -2 coconuts/fish so opp. cost of one more
coconut is 1/2 foregone fish.
MF has the comparative opp. cost advantage
in producing coconuts.
25
F
78Comparative Advantage
C
RC
Economy
C
Use RC to produce fish before using MF.
20
70
30
F
Use MF to produce coconuts before using RC.
C
MF
50
50
55
30
F
25
F
79Comparative Advantage
C
RC
Economy
C
Using low opp. cost producers first results in a
ppf that is concave w.r.t the origin.
20
70
30
F
C
MF
50
50
55
30
F
25
F
80Comparative Advantage
Economy
C
More producers with different opp. costs smooth
out the ppf.
F
81Coordinating Production Consumption
- The ppf contains many technically efficient
output bundles. - Which are Pareto efficient for consumers?
82Coordinating Production Consumption
Coconuts
Output bundle is
Fish
83Coordinating Production Consumption
Coconuts
Output bundle is and is the aggregate endowment
for distribution to consumers RC and MF.
Fish
84Coordinating Production Consumption
Coconuts
Output bundle is and is the aggregate endowment
for distribution to consumers RC and MF.
OMF
ORC
Fish
85Coordinating Production Consumption
Coconuts
Allocate efficiently say
to RC
OMF
ORC
Fish
86Coordinating Production Consumption
Coconuts
Allocate efficiently say
to RC and to MF.
OMF
ORC
Fish
87Coordinating Production Consumption
Coconuts
OMF
ORC
Fish
88Coordinating Production Consumption
Coconuts
OMF
ORC
Fish
89Coordinating Production Consumption
Coconuts
OMF
ORC
Fish
90Coordinating Production Consumption
Coconuts
MRS ? MRPT
OMF
ORC
Fish
91Coordinating Production Consumption
Coconuts
Instead produce
OMF
OMF
ORC
Fish
92Coordinating Production Consumption
Coconuts
Instead produce
OMF
OMF
ORC
Fish
93Coordinating Production Consumption
Coconuts
Instead produce Give MF same allocation
as before.
OMF
OMF
ORC
Fish
94Coordinating Production Consumption
Coconuts
Instead produce Give MF same allocation
as before. MFs utility
is unchanged.
OMF
OMF
ORC
Fish
95Coordinating Production Consumption
Coconuts
Instead produce Give MF same allocation
as before. MFs utility
is unchanged
OMF
OMF
ORC
Fish
96Coordinating Production Consumption
Coconuts
Instead produce Give MF same allocation
as before. MFs utility
is unchanged
OMF
OMF
ORC
Fish
97Coordinating Production Consumption
Coconuts
Instead produce Give MF same allocation
as before. MFs utility
is unchanged, RCs
utility is higher
OMF
OMF
ORC
Fish
98Coordinating Production Consumption
Coconuts
Instead produce Give MF same allocation
as before. MFs utility
is unchanged, RCs
utility is higher
Pareto improvement.
OMF
OMF
ORC
Fish
99Coordinating Production Consumption
- MRS ? MRPT ? inefficient coordination of
production and consumption. - Hence, MRS MRPT is necessary for a Pareto
optimal economic state.
100Coordinating Production Consumption
Coconuts
OMF
ORC
Fish
101Decentralized Coordination of Production
Consumption
- RC and MF jointly run a firm producing coconuts
and fish. - RC and MF are also consumers who can sell labor.
- Price of coconut pC.
- Price of fish pF.
- RCs wage rate wRC.
- MFs wage rate wMF.
102Decentralized Coordination of Production
Consumption
- LRC, LMF are amounts of labor purchased from RC
and MF. - Firms profit-maximization problem is choose C,
F, LRC and LMF to
103Decentralized Coordination of Production
Consumption
Isoprofit line equation is
104Decentralized Coordination of Production
Consumption
Isoprofit line equation is
which rearranges to
105Decentralized Coordination of Production
Consumption
Isoprofit line equation is
which rearranges to
106Decentralized Coordination of Production
Consumption
Coconuts
Higher profit
Fish
107Decentralized Coordination of Production
Consumption
Coconuts
The firms production possibility set.
Fish
108Decentralized Coordination of Production
Consumption
Coconuts
Fish
109Decentralized Coordination of Production
Consumption
Coconuts
Profit-max. plan
Fish
110Decentralized Coordination of Production
Consumption
Coconuts
Profit-max. plan
Fish
111Decentralized Coordination of Production
Consumption
Coconuts
Profit-max. plan
Competitive markets and profit-maximization ?
Fish
112Decentralized Coordination of Production
Consumption
- So competitive markets, profit-maximization, and
utility maximization all together causethe
condition necessary for a Pareto optimal economic
state.
113Decentralized Coordination of Production
Consumption
Coconuts
Competitive markets and utility-maximization
?
OMF
ORC
Fish
114Decentralized Coordination of Production
Consumption
Coconuts
Competitive markets, utility- maximization and
profit- maximization ?
OMF
ORC
Fish