TY - JOUR

T1 - Stability under learning of equilibria in financial markets with supply information

AU - Heinemann, Maik

PY - 2010

Y1 - 2010

N2 - In a recent paper Ganguli/Yang (2009) demonstrate, that there can exist multiple equilibria in a financial market model a' la Grossman/Stiglitz (1980) if traders possess private information regarding the supply of the risky asset. The additional equilibria differ in some important respects from the usual equilibrium of the Grossman-Stiglitz type which still exists in this model. This note shows that these additional equilibria are always unstable under eductive learning (cf. Guesnerie (2002)) and adaptive learning via least-squares estimation (cf. Marcet/Sargent (1988) or Evans/Honkapohja (2001)). Regarding the original Grossman-Stiglitz type equilibrium, the stability results are less clear cut, since this equilibrium might be unstable under eductive learning while it is always stable under adaptive learning.

AB - In a recent paper Ganguli/Yang (2009) demonstrate, that there can exist multiple equilibria in a financial market model a' la Grossman/Stiglitz (1980) if traders possess private information regarding the supply of the risky asset. The additional equilibria differ in some important respects from the usual equilibrium of the Grossman-Stiglitz type which still exists in this model. This note shows that these additional equilibria are always unstable under eductive learning (cf. Guesnerie (2002)) and adaptive learning via least-squares estimation (cf. Marcet/Sargent (1988) or Evans/Honkapohja (2001)). Regarding the original Grossman-Stiglitz type equilibrium, the stability results are less clear cut, since this equilibrium might be unstable under eductive learning while it is always stable under adaptive learning.

KW - Economics

M3 - Journal articles

VL - 30

SP - 383

EP - 391

JO - Economics Bulletin

JF - Economics Bulletin

SN - 1545-2921

IS - 1

ER -