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
