Open-Economy Macroeconomics

Question

Open-Economy Macroeconomics

 

Suppose the structure of an economy with a flexible exchange rates is represented by:

 

C = 200 + 0.85*(Y - T)                                                    L(r, Y) = 0.25*Y - 25*r

T = 200                                                                                                      M^S/P = 2250

I = 1700 - 25*r

G = 1800

NX = 900 - 200*e                        where e represents the real exchange rate.

 

(a)    Explain intuitively why net exports (NX) depend negatively on the real exchange rate.

 

 

 

(b)   Derive the equation for the IS curve.

[HINT: Recall that the equilibrium in the goods market for an open economy is given

by Y = C + I + G + NX; then solve for Y as a function of r and e]

 

 

(c)    Derive the equation for the LM curve.

[HINT: Recall that the equilibrium in the financial market is given by M^S/P = L(r,Y); then solve for Y as a function of r]

 

 

(d)   When there is perfect capital mobility, it is possible to assume that the equilibrium in international capital markets implies that interest rates here and abroad must be equal.  That is,

 

r = r^f

 

Otherwise, capital would move towards more profitable markets.  Assume that this economy cannot control the foreign interest rate (r^f).  That is, the interest rate is exogenously determined (i.e., determined outside the model).  Notice that in this case, the equilibrium in the financial market (the LM) is enough to determine equilibrium Y.  Calculate equilibrium Y if r^f = 2.

 

 

(e)    Calculate equilibrium C, I and NX. [HINT: Knowing Y and r, it is possible to pin down C and I.  Also, with Y, C, I and G and knowing that Y = C + I + G + NX, can pin down NX]

 

 

(f)    What is the value of e that guarantees equilibrium in the goods market? Now, we will study the impact of fiscal and monetary policy for both a flexible exchange rate regime (or "free floating") and a fixed exchange rate regime (or "peg").

 

Flexible Exchange Rates

 

(g)   Suppose G increases by 90.  Assuming flexible exchange rates, show graphically what happens after a expansionary fiscal policy.  Does equilibrium Y output increase?  Why?  Calculate the new equilibrium output.