Monetary Policy, Bounded Rationality, and Incomplete Markets

This paper extends the benchmark New-Keynesian model by introducing two frictions: (1) agent heterogeneity with incomplete markets, uninsurable idiosyncratic risk, and occasionally binding borrowing constraints; and (2) bounded rationality in the form of level-k thinking. Compared to the benchmark model, we show that the interaction of these two frictions leads to a powerful mitigation of the effects of monetary policy, which is more pronounced at long horizons, and offers a potential rationalization of the “forward guidance puzzle”. Each of these frictions, in isolation, would lead to no or much smaller departures from the benchmark model.