Yulei Luo

Rational Inattention and Aggregate Fluctuations

This paper introduces the rational inattention hypothesis (RI) -- that agents process information subject to finite channel constraints -- into a stochastic growth model with permanent technology shocks. We find that RI raises consumption volatility relative to output by introducing an endogenous demand shock. Furthermore, it is shown that incorporating RI can provide an additional internal propagation mechanism (measured by the impulse response function and the autocorrelation function of output growth) and generate higher variance of forecastable movements in output. However, we find that RI cannot resolve these puzzles in the RBC literature -- weak internal propagation and low variance of forecastable movements in output, even with what appears to be a very low capacity channel.

The Wealth Distribution and the Demand for Status

Standard economic theories of asset markets assume that assets are valued entirely for the consumption streams they can finance. This paper examines the introduction of the demand for status (as a function of wealth) into a model of uninsurable idiosyncratic risk—the “spirit of capitalism” (“soc”) assumption. We find that soc preferences lead to less inequality in wealth; placing wealth into the utility function leads to a shrinking wealth distribution. The drop in wealth concentration is smaller if the utility function implies status is a luxury good, but no parametrization leads to higher wealth Gini coefficients than the benchmark case. We then consider the consequences of revenue-neutral tax reforms with and without soc preferences, finding that they make little difference for this policy experiment.

Robustly Strategic Consumption–Portfolio Rules with Informational Frictions

This paper provides a tractable continuous-time constant-absolute-risk averse (CARA)-Gaussian framework to explore how the interactions of fundamental uncertainty, model uncertainty due to a preference for robustness (RB), and state uncertainty due to information-processing constraints (rational inattention or RI) affect strategic consumption-portfolio rules and precautionary savings in the presence of uninsurable labor income. Specifically, after solving the model explicitly, I compute and compare the elasticities of strategic asset allocation and precautionary savings to risk aversion, robustness, and inattention. Furthermore, for plausibly estimated and calibrated model parameters, I quantitatively analyze how the interactions of model uncertainty and state uncertainty affect the optimal share invested in the risky asset, and show that they can provide a potential explanation for the observed stockholding behavior of households with different education and income levels.

Induced Uncertainty, Market Price of Risk, and the Dynamics of Consumption and Wealth

In this paper we examine the implications of model uncertainty or robustness (RB) for consumption and saving and the market price of uncertainty under limited information-processing capacity (rational inattention or RI). First, we show that RI by itself creates an additional demand for robustness that leads to higher “induced uncertainty” facing consumers. Second, if we allow capacity to be elastic, RB increases the optimal level of attention. Third, we explore how the induced uncertainty composed of (i) model uncertainty due to RB and (ii) state uncertainty due to RI, affects consumption and wealth dynamics, the market price of uncertainty, and the welfare losses due to incomplete information. We find that induced uncertainty can better explain the observed consumption-income volatility and market price of uncertainty – low attention increases the effect of model misspecification.

What we don’t know doesn’t hurt us: rational inattention and the permanent income hypothesis in general equilibrium

This paper derives the general equilibrium effects of rational inattention (or RI; Sims 2003, 2010) in a model of incomplete income insurance (Huggett 1993, Wang 2003). We show that, under the assumption of CARA utility with Gaussian shocks, the permanent income hypothesis (PIH) arises in steady state equilibrium due to a balancing of precautionary savings and impatience. We then explore how RI affects the equilibrium joint dynamics of consumption, income and wealth, and find that elastic attention can make the model fit the data better. We finally show that the welfare costs of incomplete information are even smaller due to general equilibrium adjustments in interest rates.

A Note on Entrepreneurial Risk, Capital Market Imperfections, and Heterogeneity

Empirical evidence shows that entrepreneurs hold a large fraction of wealth, have higher saving rates than workers, and face substantial uninsurable entrepreneurial and investment risks. This paper constructs a heterogeneous-agent general equilibrium model with uninsurable entrepreneurial risk and capital market imperfections to explore the implications of uninsurable entrepreneurial risk for wealth distribution and aggregate activity in an incomplete market economy. It is shown that entrepreurial risk can substantially affect both the wealth distribution and the macroeconomy.

Long-run Consumption Risk and Asset Allocation under Recursive Utility and Rational Inattention

We study the portfolio decision of a household with limited information-processing capacity (rational inattention or RI) in a setting with recursive utility. We find that rational inattention combined with a preference for early resolution of uncertainty could lead to a significant drop in the share of portfolios held in risky assets, even when the departure from standard expected utility with rational expectations is small. In addition, we show that the equilibrium equity premium increases with the degree of inattention because inattentive investors with recursive utility face greater long-run risk and thus require higher compensation in equilibrium. Our results are robust to the presence of correlation between the equity return and the RI-induced noise and the presence of non-tradable labor income.

Rational Inattention and the Dynamics of Consumption and Wealth in General Equilibrium

We use a recursive utility version of a basic Huggett (1993) model to study the cross-sectional dispersion of consumption and wealth (relative to income). The basic model implies too little dispersion compared to the data, whereas a one-parameter extension to include rational inattention (limited information processing) delivers a better fit to both facts in general equilibrium. In particular, intertemporal substitution plays an important role in determining the two key dispersion moments via affecting the degree of optimal attention in equilibrium. Alternative models that rely on habit formation, incomplete information about current income, or borrowing constraints are not consistent with the facts we document.

Robust Permanent Income in General Equilibrium

This paper provides a tractable continuous-time constant-absolute-risk averse (CARA)-Gaussian framework to quantitatively explore how the preference for robustness (RB) affects the interest rate, the dynamics of consumption and income, and the welfare costs of model uncertainty in general equilibrium. We show that RB significantly reduces the equilibrium interest rate, and reduces (increases) the relative volatility of consumption growth to income growth when the income process is stationary (non-stationary). Furthermore, we find that the welfare costs of model uncertainty are nontrivial for plausibly estimated income processes and calibrated RB parameter values. Finally, we extend the benchmark model to consider the separation of risk aversion and intertemporal substitution, incomplete information about income, and regime-switching in income growth.

Model Uncertainty, State Uncertainty, and State-Space Models

State-space models have been increasingly used to study macroeconomic and financial problems. A state-space representation consists of two equations, a measurement equation which links the observed variables to unobserved state variables and a transition equation describing the dynamics of the state variables. In this paper, we show that a classic linear- quadratic macroeconomic framework which incorporates two new assumptions can be analytically solved and explicitly mapped to a state-space representation. The two assumptions we consider are the model uncertainty due to concerns for model misspecification (robustness) and the state uncertainty due to limited information constraints (rational inattention). We show that the state-space representation of the observable and unobservable can be used to quantify the key parameters on the degree of model uncertainty. We provide examples on how this framework can be used to study a range of interesting questions in macroeconomics and international economics.