© 2020 EMANUEL GOMES CONFIDENTIAL AND PROPRIETARY
Miguel Lebre de Freitas
Endowment economy
MACROECONOMIC ANALYSIS
Kathleen Petyarre, 'Sandhills', 2007
•
Many decisions are intertemporal They refer to choices regarding the
allocation of resources over time, such as borrowing and lending.
•
The inter-temporal model is fundamental to understand agents’
incentives to save and invest.
•
Role of temporary versus permanent shocks
Why the time dimension?
The Endowment Economy
Questions to be addressed
• How households decide how much of their income to consume today and how much to save for the future?
• How different variables affect consumption decisions?
• How is the macroeconomic equilibrium determined by consumption decisions?
• How different variables impacts on the macroeconomic equilibrium?
The Endowment Economy
Main assumptions
• Single homogenous good (numeraire)
• Production is exogenous
(no investment, no working decision)
• Representative agent
• Two period economy
• Perfect information
• Open, closed
• Government, lump sum.
• Flexible prices
Departures from these assumptions to be explored
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODELThe endowment economy
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODELThe endowment economy
Two period economy: private sector The endowment economy
At the end of period 2 all debts owed or owing must be paid off
2
(1
1)
1 2 2 20
b r b Q T C
1
(1
0)
0 1 1 1b r b Q T C
2 2 2
1 0 0 1 1
1 he present value of 1
assets
Present value of Present value of
household present and future
consumption disposable income
Household' life
(1 )
(1 ) (1 )
T inherited
C Q T
C r b Q T
r r
time wealth ( )
The two-period budget constraint of the private sector equals: 1/(1 + r) is the relative price of future consumption
• When a household borrows, it gets the right to purchase some quantity of consumption at present in return for repayment of some larger
quantity in the future.
Budget constraints
Graphical illustration The endowment economy
Endowments are points, wealth is a segment
2
1 1
(1
1) C C
r
C
1C
20
slope =-(1+r
1)
Endowment point
1E
1 r b
0
0 Q
1 T
1Q
2 T
2
2 21 0 0 1 1
1
1 1
Q T r b Q T
r
Budget constraint
Lifetime wealth
Budget constraints
Two period economy: government sector The endowment economy
At the end of period 2 all debts owed or owing must be paid off
The two-period budget constraint of the government sector equals:
1
(1
0)
0 1 1d r d G T
2
(1
1)
1 2 20
d r d G T
2 2
1 1 0 0
1 1 he present value of
initial debt Present value of Present value of
present and future government
taxes expenditures
(1 )
1 (1 )
T
T G
T G r d
r r
Budget constraints
Two period economy: the economy budget constraint The endowment economy
At the end of period 2 all debts owed or owing must be paid off
The two-period budget constraint of the
economy equals:* * *
1
(1
0)
0 1b r b TB
2 *
1 * 0 0
1 he present value of inherited NIIP Present value of
present and future taxes
(1 ) 0
1
TTB TB r b
r
* * *
2
(1
1)
1 20
b r b TB Or, in alternative:
* * 2 2
0 0 1 * 1 *
1 1
he present value of
NIIP Present value of Present value of present and future present and future GDP Absorption (national expenditure)
(1 )
(1 ) (1 )
T inherited
Q A
r b Q A
r r
Budget constraints
t t t t t t
TB Q C G Q A
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODELThe endowment economy
The first order conditions imply the equality between the MRS and the relative price The household maximizes his life-time
utility function
Subject to the budget constraint
(Note that all terms inside omega are exogenous)
Consumer problem
Optimal Consumption
The endowment economy
U u C
1 u C
21 r
2
1 1
1
1C C
r
1
1 2' 1 1
'
u C r
u C r
(Euler equation)
When the instantaneous utility function is logarithmic
The Euler equation simplifies to:
Consumption will be increasing
(decreasing) over time if the interest rate is greater (smaller) than the rate of time preference
Consumer problem
Optimal Consumption
The endowment economy
2 1ln ln
1 U C C
r
Solving together the Euler equation and the budget constraint, we get
Replacing the exogenous omega:
C
1 1 r 2 r
1
2 21 0 0 1 1
1
1 1
2 1
Q T
C r b Q T
r r
r
2 1
1
1 1
C r
C r
Graphical illustration
Optimal Consumption
The endowment economy
Borrowing and repayment:
E
1 r
1
Optimal consumption when the indifference curve is tangent to the budget constraint
0
01 1
1 r b Q T
2 2
Q T
In this case, the household : (i) Borrows from the future
(ii) To increase consumption today
C
2C
2C
1C
1(i) C
(ii)
Income expansion path (Euler)
Borrowing Constraints
Optimal Consumption
The endowment economy
Shadow interest rate (MRS)
C2
1 r
1
1 r
1
2 2 2
1
1 0 0 1 1
1 1 1
1
C Q T
r C r r r b Q T
C1
With credit constraint, the choice set is reduced
1 r b
0
0 Q
1 T
12 2
Q T E
•
Consumption smoothing requires well-functioning financial markets to allow agents to borrow and lend across periods.
•
Although individuals may form expectations about their future
disposable incomes in a systematic way, liquidity constraint
may prevent them from acting on these expectations.
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODELThe endowment economy
Changes in the interest rate
Consumption and the interest rate
The endowment economy
The intertemporal budget constraint is different from conventional, in that the price (interest rate) is both on the left-hand side and on the right-hand side
2 2 2
1 0 0 1 1
1 1
1 1 1
C Q T
C r b Q T
r r
2
1 1 1
1
1C C r
r
Three potentially opposing effects on C1
• Conventional:
• Substitution effect: C2 relatively cheaper
• Income effect: positive because C2 is cheaper
• With logarithmic utility these two effects cancel out
• Wealth effect: The value of life-time wealt declines: if Q2>0, C1 falls!
When the interest rate increases, life- time wealth falls
What happens when the interest rate increases?
Effect of an increase in the interest rate The endowment economy
C1E E
A A
C
C
´
´
C1C2 C2
Borrowers are made poorer: the positive income effect is offset
by the negative wealth effect
Lenders are made richer: ifthe elasticity of substitution is less than one, the positive income
effect may be offset by the negative wealth effect
Along this course, we assume that C1 responds negatively to an increase in the interest rate
Consumption and the interest
rate
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODELThe endowment economy
The household maximizes his life-time utility function
Subject to the budget constraint
The solution to this problem is:
Revisit Consumer problem
Optimal consumption
The endowment economy
2 1ln ln
1 U C C
r
2
1 1
1
1C C
r
C
1 1 r 2 r
1• All terms inside omega are exogenous in respect to the consumer decision
• What matters for consumption is the current value of lifetime wealth, omega.
• Whether the value of omega
corresponds to income today or in the future it does not matter
2 21 0 0 1 1
1
1 1
Q T r b Q T
r
Private sector’ s wealth and government debt The endowment economy
Households’ lifetime wealth
As long as the government respects its budget constraint, its spending will be paid for by taxes, now or in the future.
If the private sector fully internalizes the public sector budget constraint :
•
Government bonds are not private wealth:
households buy bonds today to hedge future taxation
•
The pattern of taxation over time has no effect on private wealth
• Consumption does not depend on the timing of taxation
•
Consumption is however affected by government expenditures (omega affected)
2 21 0 0 1 1
1
1 1
Q T r b Q T
r
2 2
1 1 0 0
1 1
(1 )
1 (1 )
T G
T G r d
r r
*
* 2 21 0 0 1 1
1
1 1
Q G r b Q G
r
The Ricardian Equivalence
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODELThe endowment economy
The macroeconomic equilibrium will depend on whether the economy is open or closed :
•
Open economy:
•
Closed Economy (autarky interest rate endogenous)
eventually Private consumption
National expenditure
National income
Expenditure, income, and the current account
Macroeconomic equilibrium
The endowment economy
*
* 2 21 0 0 1 1
1
1 1
2 1
Q G
C r b Q G
r r
r
*
1 1 1
; ,
1 2, ,
1 2, ,
0 1A C r Q Q G G r b G
*
1 1 1 1
,...
CA Y A r
*
1 0 0 1
Y r b Q
1 1 1a
,...
Y A r
*
0
0
b
Graphical illustration
1 r
11 1 1
CA Y A
1 r
1Y
1Q
11 1 1
A C G 1 r
1aMacroeconomic equilibrium
The endowment economy Numerical example:
*
0 1 2
0
b r G G
1
100
Q
2
80
Q
“Dark future”
1 1
1
1 80
2 100 1
C A
r
1
1
50 40 CA 1
r
The macroeconomic equilibrium will
depend on whether the economy is
open or closed
Numerical example:
Graphical illustration
Macroeconomic equilibrium
The endowment economy
1 r
1CA
11 r
1Y
11.25
Q
11 1
A C
*
1 r
11
18
CA
open economy •
the interest rate is exogenous, the current account is endogenous
1
1
50 40 82 C 1
r
1
1
50 40 18 CA 1
r
*
1 r
11.25
82 100
* *
2 1
1
1 218 1.25 80 102.5 C b r Q
* *
2 1 1 2
18 0.25 80 84.5 Y b r Q
•
Future:
2 2 2
84.5 102.5 18 S Y C
* * * *
2 2 1 1 2 2 1 1
18
CA TB r b Q C r b
Graphical illustration
Macroeconomic equilibrium
The endowment economy
1 r
1CA
11 r
1Y
11 1 1
A C G
closed economy •
Closed Economy: the current account must be zero, the interest rate is endogenous
1 r
1aAutarky interest rate:
1
1 40 0.8
50 r
a
0.8
1
1
50 40 0
1
aCA r
Example: two agents
1A
60 Q
2A
40 Q
1B 40 Q
1B 40 Q
1
1 40
60 55
2 0.8
CA
1
1 40
40 45
2 0.8
CB
1A 1A 1A 5
S Q C
1B 1B 1B 5
S Q C
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODEL THE ENDOWMENT ECONOMYAGENDA
Temporary increase in output
1 r
1CA
11 r
1Y
1*
1 r
11 1 1
A C G
• Assume CA=0 before the shock
(closed=open)
*
1 r
1Q
1Experiment 1
1 0
Q THE ENDOWMENT ECONOMY
Comparative statics
CA
11 1 1
A C G
1
0
CA
• Assume CA=0 before the shock
(closed=open)
• Temporary shock (open economy):
• At a constant interest rate
1
0
CA
C
1Q
1 1 r 2 r < 1
1 1
1 1 0
2 CA
Q
r r
open economy
*
1 r
1Q
11 r
1*
1 r
1Temporary increase in output
Experiment 1
THE ENDOWMENT ECONOMY
1 0
Q
1 r
1Y
1Comparative statics
CA
11 r
1a1 1 1
A C G 1 r
1a'
• Temporary shock (closed economy):
• The autarky interest rate must fall to induce an expansion of current
consumption equal to the increase in output.
Q
11 r
1Temporary increase in output Q1 0
Experiment 1
closed economy
1 r
1Y
1Comparative statics
THE ENDOWMENT ECONOMY
CA
1* *
1 1 o 0
Y Q r b
1 1 1
A C G
*
1 r
12 0
Q
• Assume CA=0 before the shock
(closed=open)
Q
1Anticipated (future) output expansion
Experiment 2
1 r
1*
1 r
11 r
111 r
Comparative statics
THE ENDOWMENT ECONOMY
Anticipated (future) output expansion
CA
11 1 1
A C G
*
1 r
11
0
CA <
1
0
CA <
• Private wealth increases
• At a constant interest rate (open economy):
1
*
2 1
1 1
2 1 0 C
Q r
r r
1
*
2 1
1 1 0
2 1
CA
Q r
r r
<
Q
11 r
1*
1 r
12 0
Q
Experiment 2
open economy
* *
1 1 o 0
Y Q r b 1 r
1Comparative statics
THE ENDOWMENT ECONOMY
CA
11 r
1a1 1 1
A C G
*
1 r
1The autarky interest rate must increase to prevent consumers from expanding current consumption, ahead of future income.
1 r
1a'
Q
1closed economy
Anticipated (future) output expansion
Experiment 2
2 0
Q
1 r
1 * *1 1 o 0
Y Q r b 1 r
1Comparative statics
THE ENDOWMENT ECONOMY
1 1 1
A C G
• Assume CA=0 before the shock
1 2 0
Q Q Q
Q
1Permanent output expansion
Experiment 3
1 r
1*
1 r
1Y
1*
r
1r
Comparative statics
THE ENDOWMENT ECONOMY
Y
11 1 1
A C G
• Assume CA=0 before the shock
• At a constant interest rate
*
1 1
*
1 1
2
1 1 0
2 1
CA r
Q r
r r
*
1 1
*
2 1
1 2
2 1 1
C r
Q r
r r
In case
• Impact on consumption (1:1)
• No need to smooth borrowing or lending abroad
*
r
1r
*
r
1r
Q
11 2 0
Q Q Q
Permanent output expansion
Experiment 3
1 r
1*
1 r
1open economy
Comparative statics
THE ENDOWMENT ECONOMY
1 r
1a1 1 1
A C G
• At a constant interest rate • The autarky interest rate may change, depending on the time profile of government
expenditures
2 2 2
1
1 1 1
1
aC 1 Q G 1
r C r Q G r
Q
11 r
11 2 0
Q Q Q
Permanent output expansion
Experiment 3
closed economy
Y
1Comparative statics
THE ENDOWMENT ECONOMY
1 r
1CA
1Y
11 1 1
A C G
*
1 r
1• Assume CA=0 before the shock
(closed=open)
1 0
G
Q
1Temporary fiscal expansion
Experiment 4
1 r
1*
1 r
1Comparative statics
THE ENDOWMENT ECONOMY
CA
11 1 1
A C G
*
1 r
11
0
CA <
• Assume CA=0 before the shock
(closed=open)
• At a constant interest rate
1 1
1 1
1 1 0
2
CA A
G G
r r
<
1
0
CA <
C
1G
1 1 r 2 r < 0
Q
11 0
G Temporary fiscal expansion
Experiment 4
open economy
1 r
1*
1 r
11 r
1Y
1Comparative statics
THE ENDOWMENT ECONOMY
1 r
1Y
1CA
11 r
1a1 1 1
A C G
• The increase in government spending cannot be matched by imports
• Private consumption must be completely crowded out
• The autarky interest rate must rise to induce the fall in current consumption
• Rationale: savings decline in the market for loanable funds
1 r
1a'
Q
11 r
11 0
G Temporary fiscal expansion
Experiment 4
closed economy
Comparative statics
THE ENDOWMENT ECONOMY
1 r
1Y
11 r
1*
1 r
11 1 1
A C G
*
1 r
11
0
CA <
• Assume CA=0 before the shock
• At a constant interest rate
1
0
CA <
*
0 0
b
*
1
* 0 0
1 1 0
2
C r
b
r r
0*
1
* 0
1 0
2 CA r
b
r r
<
1
Q
CA
1Increase in NIIP:
Experiment 5
THE ENDOWMENT ECONOMY
open economy
Comparative statics
1 *
* 0 0
Y 0 b r
CA
11 1 1
A C G
1
0
CA
• Assume CA=0 before the shock
• Temporary TOT shock
• Same as a temporary output shock
• Increase in consumption today
• Improvement in the Current Account
• The positive relationship between terms of trade, savings and the Current Account is known as the Harberger-Laursen-Metzler effect
1
0
CA
*
1 r
1Q
11 r
1*
1 r
1Terms of trade improvement
Experiment 6
THE ENDOWMENT ECONOMY
1
0
TT 1 r
1Y
1Comparative statics
* * 2 2 2
1 0 0 1 1 1 *
1
1 1
TT Q G b r TT Q G
r
Q C
TT P P
open economy
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODELThe endowment economy
Macroeconomic equilibrium
The endowment economy
CA
1S
1*
CA
11 r
11 r
1a A*
1 r
11A
0
CA < CA
1B 0
*
1 r
1• The world interest rate is the one that clears the world market for loanable funds
(World=closed economy)
• The small open economy is negligible: it takes the interest rate as given.
• In the figure, at the world interest rate, the home economy is running a deficit.
• Note that the autarky interest rate is above the international interest rate.
• This reflects scarcity of loanable funds at home
Small open economy and the world interest rate
• In the figure, the world interest rate is increasing, reflecting for instance, an increase in r(impatience).
• The increase in the world interest rate caused the home economy (left panel) to move from a CA deficit into a
surplus
• Note that the world interest rate jumped ahead of the autarky interest
Macroeconomic equilibrium
The endowment economy
CA
1S
1*
CA
11 r
11 r
1aA A
B
*
1 r
1B
1A
0
CA < CA
1B 0
*
1 r
1• When the world interest rate increases Experiment 1
Small open economy and the world interest rate
Sudden Stop
The endowment economy
On occasion, capital flows can suddenly stop, meaning that those who wish to borrow anew or roll over an existing loan will be unable to obtain financing.
These capital market shutdowns occur much more frequently in emerging markets.
• financial account surplus rapidly shrinks,
• requiring a decrease in current account deficit,
• requiring a sudden cut in expenditures (GNE) relative to production (GDP).
Macroeconomic equilibrium
Sudden stop
Macroeconomic equilibrium
The endowment economy
1 r
1CA
11 r
1Y
1*
1 r
11 1 1
A C G
*
1 r
11 r
1A Sudden Stop materializes as a decline in the amount a country can borrow abroad.
The current account is forced to shrink, to meet that amount.
In this case, the domestic interest rate increases above the international interest rate, reflecting the scarcity of loanable funds in the home economy.
Q
1CA
1< 0
1
0
CA <
Experiment 2
Capital flow reversal
Macroeconomic equilibrium
The endowment economy
1 r
1CA
11 r
1Y
1*
1 r
11 1 1
A C G
*
1 r
11 r
1In a more extreme case where the country
is forced to pay back existing debt (say, short term debt maturing at the time of the capital flow), the CA is forced to a positive level, and the domestic interest rate (or the shadow cost of borrowing) increases even further
Q
11
0
CA
1
0
CA
Experiment 2
Macroeconomic equilibrium
The endowment economy
1L
0 CA <
1
CA
RW1 r
1*
1
0
CA
1L 1RW
0
CA CA
1
CA
L1 r
1*
1 r
1• The World interest rate must be such that the deficit in the large home economy (L) matches the surplus in the rest of the world Large economy
• The world interest rate is the one that clears the world market for loanable funds
• The large economy influences the world interest rate.
• Suppose that the home (L) economy is hit by a temporary output expansion
• The CA schedule shifts to the right Large economy:
Macroeconomic equilibrium
The endowment economy
1L
0 CA <
1 r
1*
1
0
CA
1
CA
L1 r
1Temporary output expansion in L.
*
1 r
11L 1RW
0
CA CA
1
CA
RWExperiment 3
• Suppose that the home (L) economy is hit by a temporary output expansion
• The CA schedule shifts to the right
• At a constant interest rate, the CA deficit will decrease, causing an excess supply of loanable funds in the world economy
• The world interest rate must fall to clear the market for loanable funds.
Large economy:
Macroeconomic equilibrium
The endowment economy
1L
0 CA <
1 r
1*
1 r
1*
1
0
CA
1
CA
L1 r
1*
1 r
1'
1L 1RW
0
CA CA
1
CA
RWExperiment 3
Temporary output expansion in L.
•
INTERTEMPORAL BUDGET CONSTRAINTS•
OPTIMAL CONSUMPTION•
CONSUMPTION AND THE INTEREST RATE•
RICARDIAN EQUIVALENCE•
MACROECONOMIC EQUILIBRIUM WITH FLEXIBLE PRICES•
COMPARATIVE STATICS•
THE WORLD INTEREST RATE•
FAILURE OF RICARDIAN EQUIVALENCE•
BEYOUND THE TWO-PERIOD MODEL THE ENDOWMENT ECONOMYAGENDA
Private sector’ s wealth and government debt The endowment economy
Households’ lifetime wealth
As long as the government respects its budget constraint, its spending will be paid for by taxes, now or in the future.
If the private sector fully internalizes the public sector budget constraint :
•
Government bonds are not private wealth:
households buy bonds today to hedge future taxation
•
The pattern of taxation over time has no effect on private wealth
• Consumption does not depend on the timing of taxation
•
Consumption is however affected by government expenditures (omega affected)
2 21 0 0 1 1
1
1 1
Q T r b Q T
r
2 2
1 1 0 0
1 1
(1 )
1 (1 )
T G
T G r d
r r
*
* 2 21 0 0 1 1 *
1
1 1
Q G r b Q G
r
The Ricardian Equivalence
Change in the timing of taxation The endowment economy
All else equal, if the government decreases taxes today, government debt will increase
Since this debt must be repaid in period 2, taxes must increase in period 2:
All in all, the government shifted taxes to the future, without altering the current value of total revenues (that must equal the current value of expenditures)
•
Changing the profile of taxation had no impact on the private sector lifetime wealth:
The Ricardian Equivalence
1 2
1
1 0 T T
r
1
0
< T
1 1
0
d T
2 1
1
1 11
1T d r T r
2 21 0 0 1 1
1
1 1
Q T r b Q T
r
1 1 2
1
1 0 T T
r
The endowment economy
Since private consumption does not change, national savings are not impacted
However, the tax cut today impacts positively on the private sector disposable income. Since consumption does not change, this means that private savings must increase:
This will match the fall in government savings:
The Ricardian Equivalence
1 0 0 1 1 1
S
P r b Q T C
1 1 1 0 0
S
G T G r d
1
*
1 1 0 0 1 1
Y
S Q r b C G
Change in the timing of taxation
1P 1
0
S T
1
0
< T
1G 1
0
S T
<
In sum:
• A fall in government saving caused by temporary
tax cut is fully offset by a contemporaneous rise in private saving.
•
In effect, the private sector will save buying the
government bonds that the government is selling.
In the real life, there are many reasons why the Ricardian equivalence fails.
In what follows, we focus on three cases.
The Ricardian Equivalence will not hold exactly when:
(i) lump sum taxes are not available;
(ii) the private sector faces borrowing constraints or higher interest rates than the government sector;
(iii) households have shorter horizons than governments.
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
In the real life, there are many reasons why the Ricardian equivalence fails.
In what follows, we focus on three cases.
The Ricardian Equivalence will not hold exactly when:
(i) lump sum taxes are not available;
(ii) the private sector faces borrowing constraints or higher interest rates than the government sector;
(iii) households have shorter horizons than governments.
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
Assume that the Government subsidizes rises a consumption tax taxes today to finance a subsidy on consumption expenditures next year.
Also assume that
Since the government meets its budget constraint
…the timing of taxation does not affect private wealth.
Still, taxes now affect the relative price of consumption today versus future.
*
1 2 0
0
G G b
C1
1t
1 C2
1t
2
1r1 Q1 Q2 1r1
t
1C
1 t
2C
21 r 0
Distortionary taxation
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
The Euler equation is:
Substituting in the budget constraint, we see that current consumption depends on the tax rate.
C1 1
r
2r
1 1
t
11
2
1
11 2
1 1 1
1
C r
C r t
t
1 r
1CA
11 r
1Y
1*
1 r
11
,
1Y A
1 1 1
A C G
*
1 r
11
0
CA <
• Now consider a tax cut today to be financed by an increase in the tax rate tomorrow.
• In the open economy, private consumption increases, and a CA deficit emerges.
• In the closed economy, the interest rate must increase to offset the higher desire for consumption today.
1
0
CA <
'
1 r
1aC
1 1 r 2 r
1 1 t
1
11
0
t
<
Tax Cut under distortionary taxation THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
In the real life, there are many reasons why the Ricardian equivalence fails.
In what follows, we focus on three cases.
The Ricardian Equivalence will not hold exactly when:
(i) lump sum taxes are not available;
(ii) the private sector faces borrowing constraints or higher interest rates than the government sector;
(iii) households have shorter horizons than governments.
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
C2
E
• Households often face restriction in theaccess to credit markets.
• A tax cut today offset with more taxes tomorrow will impact one-to-one on current consumption of constrained (Hand- to-mouht) households.
1
0
< T
Tax cut open economyBorrowing constraints
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
2 2 2
C Q T
1 r
1
1 1 1
C1
C Q T
Assume that some fraction lof households in our economy are constrained on borrowing, while the remaining fraction 1-lis borrowing normally.
Also assume that
Aggregate consumption will be:
*
1 2 0
0
G G b
21 1 1 1 *
1
1 1
2 1
C Q T Q Q
r
l l r
r
Heterogeneous agents
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
Assume that some fraction lof households in our economy are constrained on borrowing, while the remaining fraction 1-lis borrowing normally.
Also assume that
Aggregate consumption will be:
*
1 2 0
0
G G b
21 1 1 1 *
1
1 1
2 1
C Q T Q Q
r
l l r
r
Heterogeneous agents
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
1 1 1
CA Q C
1
0
< T
Tax cutTax cut:
• Private consumption increases, in the proportion of constrained households, giving rise to CA<0.
• Private saving increase in the proportion of Ricardian households
• The share of government debt that is not financed by Ricardian consumers is financed by foreigners open economy
1 1
0
C T l
CA
1 T
1l < 0
Assume that some fraction lof households in our economy are constrained on borrowing, while the remaining fraction 1-lis borrowing normally.
Also assume that
Aggregate consumption will be:
*
1 2 0
0
G G b
21 1 1 1 *
1
1 1
2 1
C Q T Q Q
r
l l r
r
Heterogeneous agents
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
1 1 1
CA Q C
1
0
< T
Tax cut• In the closed economy, national expenditure cannot increase. Hence the interest rate must rise.
• The rise in the interest rate induces Ricardian consumers to save more to buy the government bonds and finance the policy.
• Consumption of Ricardian households is crowded out by the increase in the consumption of non- ricardians.
closed economy
In the real life, there are many reasons why the Ricardian equivalence fails.
In what follows, we focus on three cases.
The Ricardian Equivalence will not hold exactly when:
(i) lump sum taxes are not available;
(ii) the private sector faces borrowing constraints or higher interest rates than the government sector;
(iii) households have shorter horizons than governments.
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
• Governments are infinitely lived, while households are not.
• In the real world, it may be that governments engage in debt finance for long period of time, before rising taxes in the distant future.
• In that case, the future tax increase will not be paid by current households that are to die before this day happens.
• These households will see the tax cut as a true increase in their lifetime wealth.
THE ENDOWMENT ECONOMY
Failure of Ricardian equivalence
Heterogeneous agents
• Suppose that each household lives one period only, while the government lives two periods.
• If the government decreases taxes today – on the current generation - to be paid in the future – by the next generation, then the disposable income of current generation increases and so will do current consumption.
• If lis the fraction of households that are to die in the current period:
1 1
C T l
Heterogeneous agents The endowment economy
Failure of Ricardian Equivalence
1 1
C T l
•
Suppose that each household lives one period only, while the government lives two periods.
•
If the government decreases taxes today – on the current generation - to be paid in the future – by the next generation, then the disposable income of
current generation increases and so will do current consumption.
•
If l is the fraction of households that are to die in the current period:
•
Governments are infinitely lived, while households are not.
•
In the real world, it may be that governments engage in debt finance for long period of time, before rising taxes in the distant future.
•
In that case, the future tax increase will not be paid by current households that are to die before this day happens.
•