第23章 行业供给.ppt

Chapter Twenty-Three
Industry Supply
行业供给
Structure
Market supply
Short-run supply and equilibrium
Long-run supply and equilibrium
Long-run implications for taxation
Fixed inputs and economic rent (经济租金)
Supply From petitive Industry
How are the supply decisions of the many individual firms in petitive industry to bined to discover the market supply curve for the entire industry?
Supply From petitive Industry
Since every firm in the industry is a price-taker, total quantity supplied at a given price is the sum of quantities supplied at that price by the individual firms.
Short-Run Supply
In a short-run the number of firms in the industry is, temporarily, fixed.
Let n be the number of firms;i = 1, …,n.
Si(p) is firm i’s supply function.
Short-Run Supply
In a short-run the number of firms in the industry is, temporarily, fixed.
Let n be the number of firms;i = 1, …,n.
Si(p) is firm i’s supply function.
The industry’s short-run supply function is
Supply From petitive Industry
p
S1(p)
p
S2(p)
Firm 1’s Supply
Firm 2’s Supply
Supply From petitive Industry
p
S1(p)
p
S2(p)
p
p’
p’
S1(p’)
S1(p’)
Firm 1’s Supply
Firm 2’s Supply
S(p) = S1(p) + S2(p)
Industry’s Supply
Supply From petitive Industry
p
S1(p)
p
S2(p)
p
S(p) = S1(p) + S2(p)
p”
p”
S1(p”)
S1(p”)+S2(p”)
S2(p”)
Firm 1’s Supply
Firm 2’s Supply
Industry’s Supply
Supply From petitive Industry
p
S1(p)
p
S2(p)
p
Firm 1’s Supply
Firm 2’s Supply
S(p) = S1(p) + S2(p)
Industry’s Supply