A key property of the Aiyagari-type heterogeneous-agent models is that the equilibrium interest rate of public debt lies below the time discount rate. This fundamental property, however, implies that the Ramsey planner's fiscal policy may be time-inconsistent because the forward-looking planner...

We build a tractable heterogeneous-agent incomplete-markets model with quasi-linear preferences to address a set of long-standing issues in the optimal Ramsey taxation literature. The tractability of our model enables us to analytically prove the existence of a Ramsey steady state and establish...

The role of unconditional lump-sum transfers in improving social welfare in heterogenous agent models has not been thoroughly understood in the literature. We adopt an analytically tractable Aiyagari-type model to study the distinctive role of unconditional lump-sum transfers in reducing...

The aggregate capital stock in a nation can be overaccumulated for many different reasons. This paper studies which policy or policy mix is more effective in achieving the socially optimal (golden rule) level of aggregate capital stock in an infinite-horizon heterogeneous-agents...

The rapidly growing national debt in the U.S. since the 1970s has alarmed and intrigued the academic world. Consequently, the concept of dynamic (in)efficiency in an overlapping generations (OLG) world and the importance of the heterogeneous-agents and incomplete markets (HAIM) hypothesis to...

In infinite horizon, heterogeneous-agent and incomplete-market models, the existence of an interior Ramsey steady state is often assumed instead of proven. This paper demonstrates the critical importance of proving the existence of the Ramsey steady state when conducting theoretical or numerical...

We design an infinite-horizon heterogeneous-agents and incomplete-markets model to demonstrate analytically that in the absence of any redistributional effects of government policies, optimal capital tax is zero despite capital overaccumulation under precautionary savings and borrowing...

This paper illustrates a challenge in analyzing the learning algorithms resulting in second-order difference equations. We show in a simple monetary model that the learning dynamics do not converge to the rational expectations monetary steady state. We then show that to guarantee convergence,...

Assuming a neoclassical production technology, this paper characterizes constrained efficient intertemporal wedges for the macro aggregate as well as the micro individual allocation of dynamic Mirrleesian economies. We first construct “Pareto-Negishi weights” from the multipliers on a...

Empirical moments of asset prices and exchange rates imply that pricing kernels are almost perfectly correlated across countries. Otherwise, observed real exchange rates would be too smooth for high Sharpe ratios. However, the cross country correlation among macro fundamentals is weak. We...