UNINSURED IDIOSYNCRATIC INVESTMENT RISK

This paper augments the neoclassical growth model to study the macroeconomic effects of idiosyncratic investment risk. The general equilibrium is solved in closed form under standard assumptions for preferences and technologies. A simple condition is identified for incomplete markets to result in both a lower interest rate and a lower capital stock in the steady state: the elasticity of intertemporal substitution must be higher than the income share of capital. For plausible calibrations of the model, the reduction in the steady-state levels of aggregate savings and income relative to complete markets is quantitatively significant. Finally, cyclical variation in private investment risks is shown to amplify the transitional dynamics.

Noisy Business Cycles

This paper investigates a real-business-cycle economy that features dispersed information about the underlying aggregate productivity shocks, taste shocks, and—potentially—shocks to monopoly power. We show how the dispersion of information can (i) contribute to significant inertia in the response of macroeconomic outcomes to such shocks; (ii) induce a negative shortrun response of employment to productivity shocks; (iii) imply that productivity shocks explain only a small fraction of high-frequency fluctuations; (iv) contribute to significant noise in the business cycle; (v) formalize a certain type of demand shocks within an RBC economy; and (vi) generate cyclical variation in observed Solow residuals and labor wedges. Importantly, none of these properties requires significant uncertainty about the underlying fundamentals: they rest on the heterogeneity of information and the strength of trade linkages in the economy, not the level of uncertainty. Finally, none of these properties are symptoms of inefficiency: apart from undoing monopoly distortions or providing the agents with more information, no policy intervention can improve upon the equilibrium allocations

Socially Optimal Coordination: Characterization and Policy Implications

In recent years there has been a growing interest in macro models with heterogeneity in information and complementarity in actions. These models deliver promising positive properties, such as heightened inertia and volatility. But they also raise important normative questions, such as whether the heightened inertia and volatility are socially undesirable, whether there is room for policies that correct the way agents use information in equilibrium, and what are the welfare effects of the information disseminated by the media or policy makers. We argue that a key to answering all these questions is the relation between the equilibrium and the socially optimal degrees of coordination. The former summarizes the private value from aligning individual decisions, whereas the latter summarizes the value that society assigns to such an alignment once all externalities are internalized.Dispersed information, coordination, complementarities, volatility, inertia, efficiency

Transparency of Information and Coordination in Economies with Investment Complementarities

How do public and private information affect equilibrium allocations and social welfare in economies with investment complementarities? And what is the optimal transparency in the information conveyed, for example, by economic statistics, policy announcements, or news in the media? We first consider an environment where the complementarities are weak so that the equilibrium is unique no matter the structure of information. An increase in the precision of public information may have the perverse effect of increasing aggregate volatility. Nevertheless, as long as there is no value to lotteries, welfare unambiguously increases with an increase in either the relative or the absolute precision of public information. Hence, full transparency is optimal. This is because more transparency facilitates more effective coordination, which is valuable from a social perspective. On the other hand, when complementarities are strong enough that multiple equilibria are possible, more transparency permits the market to coordinate more effectively on either the bad or the good equilibrium. In this case, constructive ambiguity becomes optimal if there is a high risk that more transparency will lead to coordination failures.

Fairness and Redistribution: U.S. versus Europe

Different beliefs about how fair social competition is and what determines income inequality, influence the redistributive policy chosen democratically in a society. But the composition of income in the first place depends on equilibrium tax policies. If a society believes that individual effort determines income, and that all have a right to enjoy the fruits of their effort, it will chose low redistribution and low taxes. In equilibrium effort will be high, the role of luck limited, market outcomes will be quite fair, and social beliefs will be self-fulfilled. If instead a society believes that luck, birth, connections and/or corruption determine wealth, it will tax a lot, thus distorting allocations and making these beliefs self-sustained as well. We show how this interaction between social beliefs and welfare policies may lead to multiple equilibria or multiple steady states. We argue that this model can contribute to explain US vis a vis continental European perceptions about income inequality and choices of redistributive policies.

Fairness and Redistribution: US versus Europe

Different beliefs about how fair social competition is and what determines income inequality, influence the redistributive policy chosen democratically in a society. But the composition of income in the first place depends on equilibrium tax policies. If a society believes that individual effort determines income, and that all have a right to enjoy the fruits of their effort, it will chose low redistribution and low taxes. In equilibrium effort will be high, the role of luck limited, market outcomes will be quite fair, and social beliefs will be self-fulfilled. If instead a society believes that luck, birth, connections and/or corruption determine wealth, it will tax a lot, thus distorting allocations and making these beliefs self-sustained as well. We show how this interaction between social beliefs and welfare policies may lead to multiple equilibria or multiple steady states. We argue that this model can contribute to explain US vis a vis continental European perceptions about income inequality and choices of redistributive policies.

Dynamic Global Games of Regime Change: Learning, Multiplicity and Timing of Attacks

Global games of regime change–coordination games of incomplete information in which a status quo is abandoned once a sufficiently large fraction of agents attacks it–have been used to study crises phenomena such as currency attacks, bank runs, debt crises, and political change. We extend the static benchmark examined in the literature by allowing agents to take actions in many periods and to learn about the underlying fundamentals over time. We first provide a simple recursive algorithm for the characterization of monotone equilibria. We then show how the interaction of the knowledge that the regime survived past attacks with the arrival of information over time, or with changes in fundamentals, leads to interesting equilibrium properties. First, multiplicity may obtain under the same conditions on exogenous information that guarantee uniqueness in the static benchmark. Second, fundamentals may predict the eventual regime outcome but not the timing or the number of attacks. Finally, equilibrium dynamics can alternate between phases of tranquillity–where no attack is possible–and phases of distress–where a large attack can occur–even without changes in fundamentals.Global games, coordination, multiple equilibria, information dynamics, crises.

Policy with Dispersed Information

This paper studies policy in a class of economies in which information about commonly-relevant fundamentals -- such as aggregate productivity and demand conditions -- is dispersed and can not be centralized by the government. In these economies, the decentralized use of information can fail to be efficient either because of discrepancies between private and social payoffs, or because of informational externalities. In the first case, inefficiency manifests itself in excessive non-fundamental volatility (overreaction to common noise) or excessive cross-sectional dispersion (overreaction to idiosyncratic noise). In the second case, inefficiency manifests itself in suboptimal social learning (low quality of information contained in macroeconomic data, financial prices, and other indicators of economic activity). In either case, a novel role for policy is identified: the government can improve welfare by manipulating the incentives agents face when deciding how to use their available sources of information. Our key result is that this can be achieved by appropriately designing the contingency of marginal taxes on aggregate activity. This contingency permits the government to control the reaction of equilibrium to different types of noise, to improve the quality of information in prices and macro data, and, in overall, to restore efficiency in the decentralized use of information.