International economic integration yields large potential welfare effects, even in a static constant returns competitive world economy. Our method is novel. The effect of border barriers on trade flows is often inferred from gravity models. But their rather atheoretic structure precludes welfare...

Differences in real interest rates across developed economies are puzzlingly large and persistent. I propose a simple explanation: Bonds issued in the currencies of larger economies are expensive because they insure against shocks that affect a larger fraction of the world economy. I show that...

How do countries hold their financial wealth? We construct a new database of countries' claims on capital located at home and abroad, and international borrowing and lending, covering 68 countries from 1966 to 1997. We find that a small amount of capital flows from rich countries to poor...

Recently much progress has been made in developing optimal portfolio choice models accomodating time-varying opportunity sets, but unless investors are unreasonably risk averse, optimal holdings include unreasonably large equity positions. One reason is that most studies assume investors behave...

The most cost-effective policies for achieving CO2 abatement (e.g., carbon taxes) fail to get off the ground politically because of unacceptable distributional consequences. This paper explores CO2 abatement policies designed to address distributional concerns. Using an intertemporal numerical...

Typical value-at-risk (VAR) calculations involve the probabilities of extreme dollar losses, based on the statistical distributions of market prices. Such quantities do not account for the fact that the same dollar loss can have two very different economic valuations, depending on business...

This paper analyzes optimal portfolio decisions of long-horizon investors with undiversifiable labor income risk and exogenous expected retirement and lifetime horizons. It shows that the fraction of savings optimally invested in stocks is unambiguously larger for employed investors than for...