•  Many of the effects associated with asset price imbalances are, anyway, likely to be highly non-linear and complex. The implicit monetary policy reaction function would also then be non-linear and complex, and incorporate the effects of asset prices and financial imbalances.
But for the reasons previously advanced, the models we use tend to be essentially linear and we often lack the skills, and the memory, to supplement them with well reasoned analysis and robust evidence. Summing up, the difficult question of how much restriction would be needed in the face of rising asset prices calls for more study and experimentation.