I examine the risk/return tradeoff for environmental investments, and its implications for policy choice. Consider a policy to reduce carbon emissions. To what extent does the value of such a policy depend on the expected future damages from global warming versus uncertainty over those damages,...

We examine the interaction of economic and policy uncertainty in a dynamic, heterogeneous firms model. Uncertainty about foreign income, trade protection and their interaction dampens export investment. This can be mitigated by trade agreements, which are particularly valuable in periods of...

This paper studies a quantitative general equilibriummodel of the housing market where a large number of overlapping generations of homeowners face both idiosyncratic and aggregate risks but have limited opportunities to insure against these risks due to incomplete financial markets and...

This paper exploits a data rich environment to provide direct econometric estimates of time-varying macroeconomic uncertainty, defined as the common volatility in the unforecastable component of a large number of economic indicators. Our estimates display significant independent variations from...

I study irreversible investment decisions when projects take time to complete, and are subject to two types of uncertainty over the cost of completion. The first is technical uncertainty, i.e., uncertainty over the amount of time, effort, and materials that will ultimately be required to...

We re-examine the basic investment problem of deciding when to incur a sunk cost to obtain a stochastically fluctuating benefit. The optimal investment rule satisfies a trade-off between a larger versus a later net benefit; we show that this trade-off is closely analogous to the standard...

In a world of certainty, the design of environmental policy is relatively straightforward, and boils down to maximizing the present value of the flow of social benefits minus costs. But the real world is one of considerable uncertainty -- over the physical and ecological impact of pollution,...

We introduce limited liability in a model with a continuum of ex ante identical agents who face aggregate and idiosyncratic income risk. These agents can trade a complete menu of contingent claims, but they cannot commit and shares in a Lucas tree serve as collateral to back up their...