American Economic Review2019109(1), 86-120open access
We argue that an influential neo-Fisherian analysis of the effects of low interest rates depends on using perfect-foresight equilibrium analysis under circumstances where it is not plausible for people to hold expectations of that kind. We propose an explicit cognitive process by which agents may form their expectations of future endogenous variables. Perfect foresight is justified by our analysis as a reasonable approximation in some cases, but in the case of a commitment to maintain a low nominal interest rate for a long time, our reflective equilibrium implies neither neo-Fisherian conclusions nor implausibly strong predicted effects of forward guidance.
American Economic Review200494(2), 76-79open access
Taken from page 76 -- "The specter of a “liquidity trap,” originally proposed as a theoretical possibility by John Maynard Keynes (1936) but long considered to be of doubtful practical relevance, has recently created alarm among the world’s central banks. In Japan, the overnight rate has been essentially at zero for most of the time since February 1999, making further interest-rate cuts impossible. Yet until well into 2003, growth remained anemic while prices continued to fall, suggesting a need for further monetary stimulus. Since March 2001, the Bank of Japan has supplemented its “zero-interest-rate policy” with a policy of “quantitative easing,” under which additional bank reserves are supplied beyond those needed to keep overnight interest rates at zero. Yet an increase in base money of more than 50 percent failed to halt the deflation, suggesting a liquidity trap. More recently, other central banks, including the Fed, have come close enough to the zero bound to worry about how they would deal with a similar predicament. Here we first discuss whether monetary policy should actually become ineffective when the zero bound on interest rates is reached. We argue that open-market operations, even of “unconventional” types, will be ineffective if they do not change expectations about the future conduct of policy; in this sense, a liquidity trap is possible. Nonetheless, a credible commitment regarding future policy can largely mitigate the distortions created by the zero bound. We fully characterize the optimal commitment in a simple example."
We study the movements in output, consumption and hours that are forecastable from a VAR and analyze how they differ from those predicted by standard real-business-cycle models. We show that actual forecastable movements in output have a variance about one hundred times larger than those predicted by the model. We also find that forecastable changes in the three series are strongly positively correlated with each other. On the other hand, for parameters whose implications are plausible in other respects, the model implies that output, consumption, and hours should not all be expected to move in the same direction
The authors construct a dynamic general equilibrium model in which the typical industry colludes by threatening to punish deviations from an implicitly agreed-on pricing path. They use methods similar to those of F. Kydland and E. Prescott (1982) to calibrate linearized versions of both their model and an analogous perfectly concerning model. The authors then compute the two models' predictions concerning the economy's responses to a change in military spending. The responses predicted by the oligopolistic model are closer to the empirical responses estimated with postwar U.S. data than the corresponding predictions of the competitive model.
This paper provides a fairly systematic study of general economic conditions under which rational asset pricing bubbles may arise in an intertemporal competitive equilibrium framework.Our main results are concerned with non-existence of asset pricing bubbles in those economies.These results imply that the conditions under which bubbles are possible inc1uding sorne well-known examples of monetary equilibria-are relatively fragile.
Review of Economic Studies202188(4), 1979-2013open access
Observed choices between risky lotteries are difficult to reconcile with expected utility maximization, both because subjects appear to be too risk averse with regard to small gambles for this to be explained by diminishing marginal utility of wealth, as stressed by Rabin (2000), and because subjects’ responses involve a random element. We propose a unified explanation for both anomalies, similar to the explanation given for related phenomena in the case of perceptual judgments: they result from judgments based on imprecise (and noisy) mental representations of the decision situation. In this model, risk aversion results from a sort of perceptual bias—but one that represents an optimal decision rule, given the limitations of the mental representation of the situation. We propose a quantitative model of the noisy mental representation of simple lotteries, based on other evidence regarding numerical cognition, and test its ability to explain the choice frequencies that we observe in a laboratory experiment.
American Economic Review2024114(10), 3075-3118open access
We propose a model of optimal decision making subject to a memory constraint. The constraint is a limit on the complexity of memory measured using Shannon's mutual information, as in models of rational inattention; but our theory differs from that of Sims (2003) in not assuming costless memory of past cognitive states. We show that the model implies that both forecasts and actions will exhibit idiosyncratic random variation; that average beliefs will also differ from rational-expectations beliefs, with a bias that fluctuates forever with a variance that does not fall to zero even in the long run; and that more recent news will be given disproportionate weight in forecasts. We solve the model under a variety of assumptions about the degree of persistence of the variable to be forecasted and the horizon over which it must be forecasted, and examine how the nature of forecast biases depends on these parameters. The model provides a simple explanation for a number of features of reported expectations in laboratory and field settings, notably the evidence of over-reaction in elicited forecasts documented by Afrouzi et al. (2020) and Bordalo et al. (2020a).Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
American Economic Review2013103(3), 772-773open access
Report: Ad Hoc Committee on Criterion for the John Bates Clark Medal by Jonathan Gruber, Chris Paxson, Valerie Ramey and Michael Woodford. Published in volume 103, issue 3, pages 772-73 of American Economic Review, May 2013