We review the recent literature that studies new, detailed micro data on prices. We discuss implications of the new micro data for macro models. We argue that the new micro data are helpful for macro models, but not decisive. There is no simple mapping from the frequency of price changes in...

We study optimal monetary and fiscal policy in a New Keynesian model where occasional declines in agents' confidence can give rise to persistent liquidity trap episodes. Unlike in the case of fundamental-driven liquidity traps, there is no straightforward recipe for mitigating the welfare costs...