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.		
3
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*