Transcript Slides

Discussion of Aguiar Amador,
Farhi and Gopinath
Coordination and Crisis in Monetary
Unions
In a nutshell
• Very nice contribution
• Clarification of some types of interactions
between monetary and fiscal policy
• Euro area experience has shown it is a key
issue.
• Implications for optimal composition of a
currency area (low debt/high debt countries)
Set up
• Lack of commitment and lack of coordination between a
continuum of fiscal authorities and the unique monetary
authority
• Each member country defines its fiscal policy (consumption
saving decision and exogenous inflation costs) separately
from other countries.
• It does not take into account the effect of its decision on
total debt in the union: “fiscal externality”
• The Central Bank is modelled as an aggregator of fiscal
authorities.
• Monetary policy (inflation) is set centrally by the Central
Bank and depends on total debt in the union. Inflation is
constrained by an upper exogenous limit.
Ideas
• Deterministic case with no roll over risk
• Threshold equilibrium with Central bank
inflating (to the upper limit) above but not
below the threshold
• Since the debt is continuously rolled over
adjustment on the nominal rate immediately
nullifies the effect of inflation on debt
• One is left with the deadweight cost of
inflation
Implications
• In the deterministic case with no roll over risk: a
country is better off with low debt countries in a
monetary union as the incentives to inflate are
lower.
• In presence of rollover risk: a country wants low
inflation in normal times but high inflation in
crisis times
• Monetary authority more tempted to inflate if
more countries with high debt.
• So the optimal composition of the currency area
is “intermediate” for a high debt country
It is nice that the paper…
• Illuminates the effects due purely to the absence of
commitment --- It compares the Ramsey economy
(zero inflation) versus the small open economy case
with integrated fiscal and monetary authority but no
commitment) --• Versus the effects due to the absence of commitment
and of coordination (Monetary Union)
• In the latter case, there is a discrete welfare jump as an
individual country does not internalize the effect of
increasing savings marginally to get to the low inflation
equilibrium (fiscal externality)
Roll over risk
• Modeling trick:
• Exogenous possibility of rollover risk
• “Grace” period of exogenous length during which countries cannot
borrow but may choose to repay their debt at the interest rate it
was contracted upon
• This is why inflating the debt will work during the grace period (it
will have real effects)
• Multiple equilibrium: if governments default, debt goes down so
monetary authority will not inflate and repayment is tough
• If governments do not default, then monetary authority may
inflate and make repayment easier during the “grace period” (as
interest rate on debt arrears is constant)
• Equilibrium selection (“default externality” is somewhat
internalized): largest non default zone (“members of union believe
Central bank will help”)
Key results of the general model
• If many indebted countries, Central Bank always inflates hence the
nominal interest rate always prices inflation and there is no gain. The
inflation cost is paid and there is no reduction in real rate during the
“grace” period times
• If there are very few indebted countries, the Central bank never inflates
and this makes repayment difficult if a rollover crisis occurs
• If there is an intermediate number of highly indebted countries: the
Central Bank will inflate in crisis times, which is beneficial because grace
period interest rate does not adjust and hence real burden is decreased
and it will keep inflation low in normal times, which will save the inflation
costs.
• Optimal composition of a currency area follows (though there are many
equilibria )
• Question: It is assumed that debt is repaid exactly at the end of the grace
period. Can it be optimal to repay it earlier to switch back to normal
regime earlier?
Which monetary union?
• The paper has lots of references to the euro area to motivate the
analysis but:
 Continuum of small open economies which do not intract with one
another except via the response of the Central Bank to their policies
 no flexible exchange rate of the union vis-a-vis ROW (r*): MU small
in world financial markets
 Convergence of real rates is assumed (arbitrage condition r*=r+
expected inflation plays a key role in the analysis). There are
massive divergence in real rates in the euro area (indeed it is
probably a cause of the crisis)
 Objective function of the Central Bank seems far from the
institutional set up of the euro area
 Rollover risk : independent of r* for example, of debt levels
 How important is assumption 𝜌 = 𝑟 ∗ (investors opportunity cost is
equal to the discount rate of monetary and fiscal authorities)?
So…
• It does not look like the euro area
• It does not matter
• But the language should be adjusted a bit
Robustness
• Many equilibria (even in the class of symmetric ones).
Problem of equilibrium selection.
• In the model could a simple way of solving the
commitment problem be to issue debt in foreign
currency? Rollover risk is of course then an issue. It
could be interesting to look a this.
• Key assumption: the debt is continuously rolled over;
hence interest rates paid reflect immediately inflation
except in the grace period. There could be different
timing assumptions reflecting better the differences in
debt maturity structures/ the effect of “financial
repression” (see Reis et all. )
Robustness
• Role of the Central Bank: in the paper it takes inflationary
expectation as given instead of setting them (inflation
targeting framework)
• Exogenous upper limit set on inflation plays a role (bang
bang solution). If this limit was increased then we will go all
the way (hyperinflation). This is not a short cut for inflation
targeting as objective function would be quite different.
• In the paper the role of the lender of last resort (against
rollover risk) is to inflate. This would of course be at odds
with the role of a Central Bank targeting inflation.
• Since debt is exogenously given in the paper, moral hazard
issues are not much discussed. This is obviously an
important consideration in practice.
Another way of thinking about the
lender of last resort function
• Instead of inflating….the Central Bank buys risky
country debt and issues sterilization bills (money
supply unchanged) to go back to the safe no crisis
zone
• This is equivalent to replacing a default prone
asset with a default free one
• For this to be true it requires that the interest
payments on the sterilization bills be consistent
with seigniorage revenues of the Central Bank
given its inflation target
• Moral hazard issues as above.
Conclusions
• Very nice paper which generates lots of
thinking…
• As very nice papers do.