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.

Efficiency and Welfare with Complementarities and Asymmetric Information

This paper examines equilibrium and welfare in a tractable class of economies with externalities, strategic complementarity or substitutability, and incomplete information. In equilibrium, complementarity amplifies aggregate volatility by increasing the sensitivity of actions to public information; substitutability raises cross-sectional dispersion by increasing the sensitivity to private information. To address whether these effects are undesirable from a welfare perspective, we characterize the socially optimal degree of coordination and the efficient use of information. We show how efficient allocations depend on the primitives of the environment, how they compare to equilibrium, and how they can be understood in terms of a social trade-off between volatility and dispersion. We next examine the social value of information in equilibrium. When the equilibrium is efficient, welfare necessarily increases with the accuracy of information; and it increases [decreases] with the extent to which information is common if and only if agents' actions are strategic complements [substitutes]. When the equilibrium is inefficient, additional effects emerge as information affects the gap between equilibrium and efficient allocations. We conclude with a few applications, including production externalities, Keynesian frictions, inefficient fluctuations, and efficient market competition.

Optimal Monetary Policy with Informational Frictions

We study optimal monetary policy in an environment in which firms’ pricing and production decisions are subject to informational frictions. Our framework accommodates multiple formalizations of these frictions, including dispersed private information, sticky information, and certain forms of inattention. An appropriate notion of constrained efficiency is analyzed alongside the Ramsey policy problem. Similarly to the New-Keynesian paradigm, efficiency obtains with a subsidy that removes the monopoly distortion and a monetary policy that replicates flexible-price allocations. Nevertheless, “divine coincidence” breaks down and full price stability is no more optimal. Rather, the optimal policy is to “lean against the wind”, that is, to target a negative correlation between the price level and real economic activity.

Revisiting the Supply-Side Effects of Government Spending Under Incomplete Markets

This paper revisits the macroeconomic effects of government consumption in the neoclassical growth model augmented with idiosyncratic investment (or entrepreneurial) risk. Under complete markets, a permanent increase in government consumption has no long-run effect on the interest rate, the capital-labor ratio, and labor productivity, while it increases work hours due to the familiar negative wealth effect. These results are upset once we allow for incomplete markets. The very same negative wealth effect now causes a reduction in risk taking and investment. This in turn leads to a lower risk-free rate and, under certain conditions, also to a lower capital-labor ratio, lower productivity and lower wages.

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.

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

Idiosyncratic Production Risk, Growth and the Business Cycle

We introduce a neoclassical growth economy with idiosyncratic production risk and incomplete markets. The general equilibrium is characterized in closed form. Uninsurable production shocks introduce a risk premium on private equity and typically result in a lower steady-state level of capital than under complete markets. In the presence of such risks, the anticipation of low investment and high interest rates in the future discourages risk-taking and feeds back into low investment in the present. An endogenous macroeconomic complementarity thus arises, which slows down convergence and amplifies the magnitude and persistence of the business cycle. These results — contrasting sharply with those of Aiyagari (1994) and Krusell and Smith (1998) — highlight that idiosyncratic production or capital-income risk can have significant adverse effects on capital accumulation and aggregate volatility. Keywords: Capital income, Entrepreneurial risk, Fluctuations, Growth, Investment, Precautionary savings.

Incomplete Markets, Growth, and the Business Cycle

We introduce a Ramsey growth model with incomplete markets, decentralized production, and idiosyncratic technological risk. The combination of uninsurable shocks with the precautionary motive can slow down capital accumulation or give rise to persistent fluctuations even when agents are very patient and technology is strictly convex. The model generates closed-form expressions for the equilibrium dynamics under a finite or infinite horizon. Multiple steady states and poverty traps can arise from the endogeneity of the interest rate instead of the usual wealth effect. Depending on the economy's parameters, the local dynamics around a steady state are locally unique, totally unstable or locally undetermined, and the equilibrium path can be attracted to a limit cycle. In calibrated examples, financial incompleteness substantially slows down convergence to the steady state and thus increases the persistence of aggregate shocks.