In: Economics
IS-LM Model (Closed Economy)
The following equations describe a small open economy.
[Figures are in millions of dollars; interest rate (i) is in percent]. Assume that the price level is fixed.
Goods Market
C = 250 + 0.8YD
YD = Y + TR – T
T = 100 + 0.25Y
I = 300 – 50i
G = 350; TR = 150
Money Market
L = 0.25Y – 62.5i
Ms/P = 250
Goods market equilibrium condition: Y = C + I + G + X-M
Money market equilibrium condition: L = Ms/P
a) What is the equation that describes the IS curve (YIS)?
b) What is the equation describing the LM curve (YLM)?
c) What are the equilibrium levels of income (Yo) and interest rate (io)
(a)
In goods market equilibrium, Y = C + I + G + X - M
Y = 250 + 0.8[Y + 150 - (100 + 0.25Y)] + 300 - 50i + 350 [Since X = M = 0]
Y = 900 + 0.8(Y + 150 - 100 - 0.25Y) - 50i
Y = 900 + 0.8(0.75Y + 50) - 50i
Y = 900 + 0.6Y + 40 - 50i
0.4Y = 940 - 50i
Y = 2350 - 125i..........(IS equation)
(b)
In money market equilibrium, L = Ms/P
0.25Y – 62.5i = 250
0.25Y = 250 + 62.5i
Y = 1000 + 250i.........(LM equation)
(c)
In equilibrium, YIS = YLM.
2350 - 125i = 1000 + 250i
375i = 1350
i = 3.6
Y = 1000 + (250 x 3.6) = 1000 + 900 = 1900