Equilibrium Multiplicity in Aiyagari and Krusell-Smith
Repeatedly solving the Aiyagari (1994) model with random parameters, we construct hundreds of examples with multiple stationary equilibria. We never find multiplicity with risk aversion less than ≈ 1.49, depreciation less than ≈ 0.19, or income persistence less than ≈ 0.47, and multiplicity requires a disaster state for income. In cases with multiplicity, the lowest rental rate occurs near depreciation times the capital share. It is possible for the economy, without a change in fundamentals, to transition rationally from a higher-rate equilibrium to one with a lower rental rate, lower inequality, and lower welfare (for most agents). We also construct the first Krusell and Smith (1998) examples with multiple recursive competitive equilibria.
Working Papers of the Federal Reserve Bank of Cleveland are preliminary materials circulated to stimulate discussion and critical comment on research in progress. They may not have been subject to the formal editorial review accorded official Federal Reserve Bank of Cleveland publications. The views expressed in this paper are those of the authors and do not represent the views of the Federal Reserve Bank of Cleveland or the Federal Reserve System.
Suggested Citation
James Walsh, Kieran, and Eric R. Young. 2024. “Equilibrium Multiplicity in Aiyagari and Krusell-Smith.” Federal Reserve Bank of Cleveland, Working Paper No. 24-13. https://doi.org/10.26509/frbc-wp-202413
This work by Federal Reserve Bank of Cleveland is licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
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