Robustness and macroeconomic policy

This paper considers the design of macroeconomic policies in the face of uncertainty. In recent years, several economists have advocated that when policymakers are uncertain about the environment they face and find it difficult to assign precise probabilities to the alternative scenarios that may characterize this environment, they should design policies to be robust in the sense that they minimize the worstcase loss these policies could ever impose. I review and evaluate the objections cited by critics of this approach. I further argue that, contrary to what some have inferred, concern about worst-case scenarios does not always lead to policies that respond more aggressively to incoming news than the optimal policy would respond absent any uncertainty.Macroeconomics - Econometric models

Evaluating the role of labor market mismatch in rising unemployment

Recent labor market trends have raised concerns that the unemployment rate is high not because employers are reluctant to hire but because they are unable to hire. These concerns, if true, would cast doubt on using monetary policy to stimulate the labor market, since it works by encouraging firms to hire more. Using a matching function approach, the author finds that a shock that makes it more difficult for firms to hire qualified applicants would by itself imply an unemployment rate of no more than 7.1 percent, much below the actual unemployment rate during the past two years. Hence, the recent patterns in unemployment and vacancy data do not necessarily rule out a role for monetary policy.Labor market ; Unemployment

Economic theory and asset bubbles

The author summarizes what economic theory tells us about when asset price bubbles can occur and what the welfare implications are from bursting them. In some cases, bursting a bubble may make society worse off by exacerbating the market distortions that give rise to the bubble in the first place.Asset-liability management ; Asset pricing

Policymaking under uncertainty: Gradualism and robustness

Some economists have recommended the robust control approach to the formulation of monetary policy under uncertainty when policymakers cannot attach probabilities to the scenarios that concern them. One critique of this approach is that it seems to imply aggressive policies under uncertainty, contrary to the conventional wisdom of acting more gradually in an uncertain environment. This article argues that aggressiveness is not a generic feature of robust control.

Why don't recessions encourage more R&D spending?

Economists sometimes argue that recessions promote activities that ultimately contribute to long-run growth. But evidence suggests research and development, one important source of economic growth, falls rather than rises during recessions, even for firms that do not appear to be credit constrained. The author discusses an alternative explanation for this pattern.Research and development

The cost of business cycles and the benefits of stabilization

This article reviews the social cost of U.S. postwar business cycle fluctuations, first calculated by Lucas (1987). Recent work suggests this cost is considerably larger than suggested by Lucas. Despite this, the author argues that it is not obvious that policymakers should have pursued a more aggressive stabilization policy over the postwar period. Still, because volatility is costly, stable growth remains a desirable goal.Business cycles

On the timing of innovation in stochastic Schumpeterian growth models

Recent work has revived the Schumpeterian hypothesis that recessions facilitate innovation and growth. But a major source of productivity growth, research and development, is actually procyclical. This paper argues that while it is optimal to concentrate growth enhancing activities in downturns, dynamic spillovers inherent to the R&D process lead private agents to concentrate too much of their R&D activity in booms, precisely when its social cost is highest. Thus, while previous literature has argued recessions promote growth and intertemporal substitution is a desirable consequence of fluctuations, in the case of R&D recessions discourage growth and intertemporal substitution proves to be a social liability.Research and development

On the Timing of Innovation in Stochastic Schumpeterian Growth Models

Recent work has revived the Schumpeterian hypothesis that recessions facilitate innovation and growth. But a major source of productivity growth, research and development, is actually procyclical. This paper argues that while it is optimal to concentrate growth-enhancing activities in downturns, dynamic spillovers inherent to the R&D process lead private agents to concentrate too much of their R&D activity in booms, precisely when its social cost is highest. Thus, while previous literature has argued recessions promote growth and intertemporal substitution is a desirable consequence of fluctuations, in the case of R&D recessions discourage growth and intertemporal substitution proves to be a social liability.

The Cost of Business Cycles Under Endogenous Growth

In his famous monograph, Lucas (1987) put forth an argument that the welfare gains from reducing the volatility of aggregate consumption are negligible. Subsequent work that revisited Lucas' calculation continued to find only small benefits from reducing the volatility of consumption, further reinforcing the perception that business cycles don't matter. This paper argues instead that fluctuations can affect welfare by affecting the growth rate of consumption. I present an argument for why fluctuations can reduce growth starting from a given initial consumption, which could imply substantial welfare effects as Lucas (1987) already observed in his calculation. Empirical evidence and calibration exercises suggest that the welfare effects are likely to be substantial, about two orders of magnitude greater than Lucas' original estimates.

A leverage-based model of speculative bubbles

This paper examines whether theoretical models of bubbles based on the notion that the price of an asset can deviate from its fundamental value are useful for understanding phenomena that are often described as bubbles, and which are distinguished by other features such as large and rapid booms and busts in asset prices together with high turnover in asset ownership. In particular, I focus on riskshifting models similar to those developed in Allen and Gorton (1993) and Allen and Gale (2000). I show that such models could explain these phenomena, and discuss under what conditions booms and speculative trading would emerge. In addition, I show that these models imply that speculative bubbles can be associated with low rather than high premia on loans, in accordance with observations on credit conditions during episodes in which asset prices boomed and crashed.Speculation