Handout
#10: 有關 Growth
Models
Harrod-Domar Growth Model
3 個內生變數:Y, K, N
3 個方程式:
(1) Y = K/α
(2) sY = ΔK
(3) ΔN/N = n
廠商的動態行為假設:
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> = < |
s/α |
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> = < |
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↑ |
ye |
y |
ye |
ye |
不變 |
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↓ |
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↑ |
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Accelerator Principle (Chapter 16會介紹) 加上Multiplier Effect |
s/α:"保證成長率" (warranted rate of growth)
n:"自然成長率" (natural rate of growth)
均衡成長的條件: s/α = n 不穩定,叫 knife-edge growth
註:若加上折舊,則是 s/α = n + d 或 s.1/α = n + d
或 s.Y/K = n + d,此即課本 (11.7) 式。
或 s.Y/N =
( n
+ d )
K/N,此即課本
(11.8) 式。
Solow Growth Model
(1) 式改為 neoclassical production function,α 變成是
variable,而非 fixed parameter,即可得穩定的均衡成長。