Macroeconomic Chapter 3：Determination of National Income Equilibrium

 Chapter 3

这个chapter要先知道3个sector economy

two sector economy 这个没有tax

three sector economy 这个有government tax

four sector economy 这个有government tax和 net export

Yd= C+S

for two sector, Yd=Y because in two sector, there is no tax exists

for three sector, Yd=(Y-T)

• APC= C/Yd
• MPC=change in C/change in Yd
• C=a + bYd
•  b=MPC
• Y=C when saving is zero, Y= C + S
• APS=S/Yd
• MPS= change in S / change in Yd
• APC + APS = 1
• APC= 1 - APS
• APS= 1- APC
• MPC+MPS=1
• MPS= 1- MPC
• MPC= 1- MPS
• S= -a + (1-b)Yd
• 1-b=MPS
• 1-MPC=MPS
• a= saving when disposable income is zero