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Rare Disasters and Asset Markets in the Twentieth Century. Barro QJE, 2006 Presentation by Serdar Aldatmaz Spring, 2010. Background. Mehra-Prescott, 1985 Equity premium puzzle Rietz, 1988 Low-probability economic disasters might be the solution. Preview of Results.
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Rare Disasters and Asset Markets in the Twentieth Century Barro QJE, 2006 Presentation by Serdar Aldatmaz Spring, 2010
Background • Mehra-Prescott, 1985 • Equity premium puzzle • Rietz, 1988 • Low-probability economic disasters might be the solution
Preview of Results • Inclusion of rare disasters into Mehra and Prescott’s model can explain asset-market puzzles • Equity-premium puzzle • Low real rate of return on government bills • Low expected real interest rates during major wars
Outline • The Model • Review of economic disasters • Calibration Results • Extensions • Concluding Remarks
The Model • Lucas Tree Model • Exogenous, stochastic production • Neither investment, nor depreciation • Allows for capital formation in the extension • Consumption equals output • Two assets • Equity claim on t+1 output • Risk-free asset, which partially defaults in disasters
Solution without Rare Disasters • Solving for the agent’s maximizationproblem;
Modelling Rare Disasters • ut+1 is i.i.d w/ N(0, σ2) • σ and γare known • p is the probability of disaster (constant) • b is the size of contraction in case of a disaster
Modelling Default • Default occurs with probability qwhen a v-type disaster occurs • Default wipes out the fraction d of the return on the government bill • Default does not affect equities and real GDP
Solution of the Model - Price • Price of one-period equity claim:
Solution of the Model - Returns • Expected rate of return on one-period equity:Et(Ret+1)=Et(At+1)/Pt1 • Return on government bills: (Assumption: d=b)
Solution of the Model - Equity Premium • The difference between the two returns: • Increasing in p & θ & b=d • Decreasing in q
Outline • The Model • Review of economic disasters • Calibration • Extensions • Concluding Remarks
Outline • The Model • Review of economic disasters • Calibration • Extensions • Concluding Remarks
Calibration of Disaster Parameters • Probability of disasters • 60 occurrences for 35 countries over 100 years • p = 1.7% • Distribution of b from realized contractions • Default probability • 25 partial defaults out of 60 events • q = 40%
Calibration of Other Parameters • σ = 0.02 • γ = 0.025 • ρ = 0.03 • θ = 3 or 4
What other puzzles can be explained? • Why do expected real interest rates fall during wars? • Perceived probability, p, of future economic disaster increases
Outline • The Model • Review of economic disasters in the twentieth century • Calibration • Extensions • Concluding Remarks
Duration and Capital Formation • Main results do not change when we allow for finite and various length disasters • When we incorporate capital formation, invested and depreciation, the model still predicts similar equity premium results based on the calibration
Outline • The Model • Review of economic disasters in the twentieth century • Calibration • Extensions • Concluding Remarks
Concluding Remarks • Low-probability disasters explain the equity premium puzzle along with other asset market puzzles • Future research • Incorporate stochastic variations in p • Option prices, insurance premiums, prices of gold etc. • Relax i.i.d assumptions