Macroeconomic
Winter Term 2017
Assignment 2
Due: Drop Box 2nd Floor Dunning Hall by 12 noon on Thursday, 16 February
No late submissions will be accepted
No “Photocopied” answers will be accepted
Group submissions of four only will be accepted
The assignment is worth 100 points
Section A (40%): Short questions
Read the following statements and indicate whether they are True, False or
Uncertain. Briefly, but carefully, explain the economic intuition behind your
answer using diagrams and examples where appropriate. All answers have equal
value. NO MARKS WILL BE GIVEN FOR UNSUPPORTED WORK.
A.1 The empirical evidence on the strength of the income versus the substitution
effect cited in the text (page 437) indicates that, if anything, the income effect
dominates. This in turn suggests that a rise in interest rates will tend to raise
consumption spending, making it more difficult for central banks to control inflation
by using interest rates to slow aggregate demand.
A.2 Ricardian equivalence implies that consumers will not respond to a tax cut,
preferring instead to save part of their income to pay for future tax increases. Given
this, a policy of lowering taxes to stimulate demand will be ineffective.
A.3 Shifts over time in the relationship between inflation and unemployment (the
Phillips Curve) have been due solely to changes in expected inflation.
A.4 A shift inward in the Beveridge can be taken as evidence that the labour market
is functioning more efficiently.
Section B (60%): Long questions
B1. (30%) Consumption function with credit constraints and lump-sum taxes
Consider an economy with two groups of consumers, the less well off, who have no
initial wealth and are credit constrained (they cannot borrow or lend to smooth
consumption) and the rich who have an initial endowment of wealth in period 1 of
V1 and who can borrow or lend to smooth consumption. For simplicity, each has the
same level of labour income in period 1 (Y1
L ). The two different consumption
functions for period 1 are:
C1
p = Y1
L -T1 (1)
2
C1
r =? V1 +Y1
L -T1 +
Y2
L -T2
1+ r
?
?
? ?
?
?, 0 <1 (2)
Equation (2) is the same as (18) in the main text (page 434). The coefficient ? is as
defined by equation (17) in the text (page 433).
For convenience assume that the population is normalized to one and that the
fraction of poor people is µ.
1. Derive the economy’s aggregate consumption function defined as:
C1 = µC1
p +(1-µ)C1
r (3)
In addition, evaluate the marginal propensity to consume out of disposable
income:
?C1
? Y1
L
( -T1)
Compare your results with an economy in which there are no credit-constrained
households (e.g., µ = 0). Would a reduction in the number credit-constrained
households increase or decrease consumption? Explain your reasoning.
Suppose now that the government enacts a debt-financed reduction in current taxes
(T1 ); that is, they keep planned spending unchanged. Assume as well that the public
understands that the government will be raising taxes in the future in order to
balance its budget and in particular to pay down the debts incurred in period 1. That
is, all consumers are Ricardian and realize that:
dT1 +
dT2
1+ r
= 0 (4)
The above follows from the condition of the inter-temporal budget constraint for the
government.
2. Derive the effect that this policy will have on present consumption ( C1 ).
Compare as well, this situation to one where there are no credit-constrained
households. Has the government’s policy helped or hindered credit-constrained
consumers? In other words, has welfare increased or decreased?
The other option for the government is to lower government spending by an
amount equal to the tax cut.
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3. Derive the effect on C1 of two different scenarios:
a. A temporary tax cut financed by a reduction in G1 (that is,
dG1 = dT1 and dG2 = dT2 = 0 )
b. Compare the above results to a permanent cut in government spending
(that is, dG1 = dT1 = dG2 = dT2 ). In this case, you can assume that r = f .
How are your results affected by the existence of credit-constrained
consumers?
B2. (30%) Aggregate demand
The goods market equilibrium condition is given by:
(1)
The variables are as defined in the text (equation (13), page 456). The coefficients
are given by:
The coefficient m! =1/(1- DY ) >1is the Keynesian multiplier, while DY , Dr and Deare
partial derivatives of the private demand, , where is confidence. The
variables with bars represent long-run values. Remember that r and are the real
current and long-run risky or market interest rates, respectively.
At the central bank, diligent hard-working economists have found a definition of
money that proves to be stable in relation to Y, i and P, where i is the short-run
nominal rate of interest. The money demand equation is given by:
L(Y, i) = kY ? e-ßi where k > 0; ? > 0 and ß > 0 (2)
At any point in time, the real demand for money equals the real supply (M/P):
kY ? e-ßi = M
P (3)
1. Based on equations (2) and (3), derive a monetary-policy rule for the central
bank. In other words, the central bank will use what it knows about the money
demand function to set its short-term policy rate (i
p ). Qualitatively, how does
such a rule differ from the Taylor Rule (equation (21), page 461 in the text)?
2. Illustrate, using a diagram (similar in spirit to that used in class) how the
aggregate demand (AD) curve is derived from the interaction of the central
bank’s policy rule with the goods market equilibrium condition (equation (1)
y - y =a1(g - g)-a2 (r - r)+ v
a1 = m! G
Y
?
?
? ?
?
?, a2 = -m! Dr
Y
?
?
? ?
?
?, v = m! e De
Y (lne - lne )
D = D(Y
+
, r
-
, e
+
) e
r
4
above). Then, using the monetary policy rule and the goods market equilibrium
condition, derive algebraically the AD curve in the following form:
y - y =a (p - p *) +? v -a2?ˆ +a1 ( (g - g)) (4)
3. Find expressions for the coefficients a and ? in terms of the underlying
parameters of the system. Next write the AD curve with (p – p*
) on the left-hand
side and then discuss how its slope is related to ß, the interest rate elasticity of
money demand and ? the income elasticity of money demand. Discuss as well
how these two slopes would affect how shocks shift the AD curve written with
(p – p*
) on the left-hand side.
During the 1970s and early 80s, both Canada and the United States experimented
with using a monetary policy rule based on estimated money-demand functions. In
Canada’s case, the interest elasticity of money demand (in absolute value) was
higher than that of the United States ( ßCAN > ßUSA ), although each was estimated to
be less than one. At the same time, the income elasticity for each was roughly the
same (?CAN ??USA ).
4. To examine the role played by different vales of ß’s, assume that Canada and the
United States start out with the same inflation rate and output level (in per
capita terms) and that they both face identical SRAS curves. This is illustrated in
the diagram below, where two AD curves have been plotted. In answering the
following three questions use the diagram and be sure to support your answers.
a. Which curve would represent Canada’s and which the United States’ and
why?
b. If there were a common short-run negative supply shock (SRAS moves up
and to the left), what would be the initial effect on inflation and output in
each country? Explain why the effects would be different.
c. If there were a common positive demand shock (say v rises), what would
be the initial effects on both inflation and output in each country? Again,
explain why they would be different.
[Hint: In answering parts b. and c. you should make reference to the
monetary rule you derived in part 1.]
5
AD and SRAS
p
y y
SRAS
AD
AD
–
p = p*