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by Mark
Aguiar and Gita Gopinath
No. 2, September 2004 - December 2004
Motivation for the Research
World capital markets have experienced large-scale sovereign
defaults on a number of occasions,
the most recent being Argentina’s default in 2002. While Argentina, which has
experienced five default or restructuring episodes in the last 180 years, may
be an extreme case, sovereign defaults occur with some frequency in emerging
markets. Other characteristics of emerging markets are that defaults occur in
equilibrium, interest rates and net exports are countercyclical, and interest
rates and current accounts are positively correlated.
This paper develops a quantitative
model of debt and default in a small open economy to match the above facts,
with the aim of explaining the dynamics that produce these
characteristics.
Research
Approach
The authors develop a model of a small open economy that receives
a stochastic endowment stream and trades a single good
and a single asset, a one-period
bond, with the rest of the world. To emphasize the distinction between the
roles of transitory and permanent shocks, they present
two extreme cases of their model.
Model I represents the case in which the only shock is a transitory shock
around a linear trend; Model II represents the case in which
the trend itself is stochastic.
The model is solved numerically, using the discrete state-space method.
To
improve on the results, the authors augment Model II with
a phenomenon observed in many
default episodes—bailouts. They model bailouts as a transfer from an unmodeled
third party
to creditors in the case of default.
Key Findings
- The model’s ability to match the facts in the data improves
substantially when the productivity process is characterized
by a volatile stochastic trend
as opposed to transitory fluctuations
around a stable trend.
- For models with purely transitory shocks,
default is a rare event, as it occurs on average only once every
1,250 years. This, in turn,
leads to a counterfactually stable interest-rate process. Moreover,
the cyclicality of the interest rate is the opposite of the cyclicality
of net exports, while
in the data both are countercyclical and positively correlated
in emerging markets.
- The
rate of default increases by a factor of ten when the model
with the stochastic trend is substituted for the model
with transitory
shocks. Furthermore, both
the current account and interest
rates are countercyclical and positively correlated.
- Allowing
for bailouts of fairly modest levels compared with those
observed in practice enables the
model to match the extreme rates of default observed in many
Latin American economies. The model also matches the countercyclicality
of net exports and interest rates.
However, by breaking the tight link between default and interest
rates, the model fails to produce
reasonable volatility in the interest rate.
- While the predictions
remain short of matching the magnitudes shown in the data,
the predicted signs
of the correlations
of income, net exports, and the interest rate are in line
with empirical facts.
Implications
The reason a model with
trend
shocks performs better
than one with
transitory shocks is that in an environment with trend
shocks, a given probability of default is associated
with a smaller
borrowing cost at
the margin. This, in
turn, rests on the fact that trend shocks have a greater
impact on the propensity to default than do standard
transitory shocks,
making interest
rates relatively
less sensitive to the amount borrowed and relatively
more sensitive to the realization of the shock.
Full text of Working
Paper 04-5 
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