ECU22012 Intermediate Economics B Problem Set 4
Hello, dear friend, you can consult us at any time if you have any questions, add WeChat: daixieit
Intermediate Economics B
Problem Set 4
1. Consider an open economy characterised by the equations below
C = c0 + cl (Y − T)
I = d0 + dl Y
IM = ml Y
X = xl Y*
The parameters ml and xl are the propensities to import and export. Assume that the real exchange rate is ﬁxed at a value of 1 and treat foreign income, Y* , as ﬁxed. Also, assume that taxes are ﬁxed and that government purchases are exogenous (i.e. decided by the government). We explore the eﬀectiveness of changes in G under alternative assumptions about the propensity to import.
a) Write the equilibrium condition in the market for domestic goods and solve for Y.
b) Suppose government purchases increase by one unit. What is the eﬀect on output? (Assume that 0 < ml < cl + < 1. Explain why.)
c) How do net exports change when government purchases increase by one unit?
Now consider two economies, one with ml = 0.5 and the other with ml = 0.1. Each economy is characterised by (cl + dl ) = 0.6.
d) Suppose one of the economies is much larger than the other. Which economy do you expect to have the larger value of ml ? Explain.
e) Calculate your answers to parts (b) and (c) for each economy by substituting the appropriate parameter values.
f) In which economy will ﬁscal policy have a larger eﬀect on output? In which economy will ﬁscal policy have a larger eﬀect on net exports?
2. In chapter 3, we have assumed that the ﬁscal policy variables G and T are indepen- dent of the level of income. In the real world, however, this is not the case. Taxes typically depend on the level of income and so tend to be higher when income is higher. In this problem, we examine how this automatic response of taxes can help
reduce the impact of changes in autonomous spending on output. Consider the following behavioural equations:
C = c0 + cl Y
T = t0 + tl Y
YD = Y − T
G and I are both constant. Assume that tl is between 0 and 1.
a) Solve for equilibrium output.
b) What is the multiplier? Does the economy respond more to changes in au- tonomous spending when tl is 0 or when tl is positive? Explain.
c) Why is ﬁscal policy in this case called an automatic stabiliser?