Discussion Paper

No. 2009-44 | October 09, 2009
A Tale of Two Debt Crises: A Stochastic Optimal Control Analysis


Banks should evaluate whether a borrower is likely to default. The author applies several techniques in the extensive mathematical literature of stochastic optimal control/dynamic programming to derive an optimal debt in an environment where there are risks on both the asset and liabilities sides. The vulnerability of the borrowing firm to shocks from either the return to capital, the interest rate or capital gain, increases in proportion to the difference between the Actual and Optimal debt ratio, called the excess debt. As the debt ratio exceeds the optimum, default becomes ever more likely. This paper is "A Tale of Two Crises" because the analysis is applied to the agricultural debt crisis of the 1980s and to the sub-prime mortgage crisis of 2007. A measure of excess debt is derived, and the author shows that it is an early warning signal of a crisis.

JEL Classification:

C61, D81, D91, D92


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Cite As

Jerome L. Stein (2009). A Tale of Two Debt Crises: A Stochastic Optimal Control Analysis. Economics Discussion Papers, No 2009-44, Kiel Institute for the World Economy. http://www.economics-ejournal.org/economics/discussionpapers/2009-44

Comments and Questions

Peter Clark - Comment
November 23, 2009 - 08:57

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Tassos Malliaris - Comment
December 04, 2009 - 09:12

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Anonymous - Referee Report
December 08, 2009 - 14:30

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John Stachurski - Decision Letter
December 14, 2009 - 10:01

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