When commitment is lacking, intertemporal trade is facilitated with the use of exchange media--interpreted broadly to include monetary and collateral assets. We study the properties of a model commonly used to motivate monetary exchange, extended to include a physical asset whose expected...

We analyze dynamic risk-sharing contracts between profit-maximizing insurers and risk-averse agents who face idiosyncratic income uncertainty and can self-insure through savings. We study Markov-perfect insurance contracts in which neither party can commit beyond the current period. We show that...

A government that cannot commit to future policy choices faces a trade-off that explains the level of debt. On the one hand, there is an incentive to increase debt and delay taxation, so as to reduce current distortions. On the other hand, inflating current prices lowers the real value of...

This paper develops and analyzes a macroeconomic model in which aggregate growth and fluctuations arise from the discovery and diffusion of new technologies; there are no exogenous aggregate shocks. The temporal behavior of aggregates is driven by individuals' efforts to innovate and/or make use...

When young individuals face binding debt constraints, their human capital investments will be insufficiently financed by private creditors. If generations overlap, then a well-designed fiscal policy may be able to improve human capital investments by replacing missing capital markets with an...