We dissect the comovement patterns of the macroeconomic data, identify a single shock that accounts for the bulk of the business-cycle volatility in the key quantities, and use its empirical properties to appraise parsimonious models of the business cycle. Through this lens, the data appears to...

We study the Ramsey policy problem in an economy in which public debt contributes to the supply of assets that private agents can use as buffer stock and collateral, or as a vehicle of liquidity. Issuing more debt eases the underlying financial friction. This raises welfare by improving the...

We develop a tractable method for augmenting macroeconomic models with autonomous variation in higher-order beliefs. We use this to accommodate a certain type of waves of optimism and pessimism that can be interpreted as the product of frictional coordination and, unlike the one featured in the...

We study the Ramsey policy problem in an economy in which firms face a collateral constraint. Issuing more public debt alleviates this friction by increasing the aggregate quantity of collateral. In so doing, however, the issuance of more debt also raises interest rates, which in turn increases...

We review how realistic frictions in information and/or rationality arrest general equilibrium (GE) feedbacks. In one specification, we maintain rational expectations but remove common knowledge of aggregate shocks. In another, we replace rational expectations with Level-k Thinking or a smooth...

A long-standing issue in the theory of monetary policy is that the same path for the interest rate can be associated with multiple bounded equilibrium paths for inflation and output. We show that a small friction in memory and intertemporal coordination can remove this indeterminacy. This leaves...

We study how fiscal deficits are financed in environments with two key features: (i) nominal rigidity and (ii) a violation of Ricardian equivalence due to finite lives or liquidity constraints. In such environments, deficits contribute to their own financing via two channels: a boom in real...

We show that international trade in goods is the main determinant of international equity portfolios and offers a compelling -- theoretically and empirically -- resolution of the portfolio home bias puzzle. The model implies that investors can achieve full international risk diversification if...

This paper shows how rational investors can have different degrees of optimism regarding the prospects of the economy, even if they share exactly the same information regarding all economic fundamentals. The key is that heterogeneity in expectations regarding endogenous outcomes can emerge as a...

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...