Over the past century, America changed from a nation of distinct cities separated by farmland, to a place where employment and population density is far more continuous. For some purposes, it makes sense to think of the U.S. as consisting of a number of contiguous megaregions. Using the...

This paper presents an analysis of diversification and portfolio value at risk for heavy-tailed dependent risks in models with multiple common shocks. We show that, in the framework of value at risk comparisons, diversification is optimal for moderately heavy-tailed dependent risks with common...

In the last 50 years, population and incomes have increased steadily throughout much of the Sunbelt. This paper assesses the relative contributions of rising productivity, rising demand for Southern amenities and increases in housing supply to the growth of warm areas, using data on income,...

New developments in the world economy have triggered research designed to better understand the changes in trade and investment patterns, and the reorganization of production across national borders. Although traditional trade theory has much to offer in explaining parts of this puzzle, other...

This paper explores a macroeconomic model of the business cycle in which stickiness of information is pervasive. We start from a familiar benchmark classical model and add to it the assumption that there is sticky information on the part of consumers, workers, and firms. We evaluate the model...

This paper discusses five questions the incoming chairman of the Federal Reserve must ponder as he assumes his new post. How important are monetary rules? Should the Fed adopt inflation targeting? Should he be free with his opinions? Should he be a high-profile public figure? Is it more...

The division of America into red states and blue states misleadingly suggests that states are split into two camps, but along most dimensions, like political orientation, states are on a continuum. By historical standards, the number of swing states is not particularly low, and America's...

The present paper introduces new sign tests for testing equality of conditional distributions of two (arbitrary) adapted processes as well as for testing conditionally symmetric martingale-difference assumptions. Our analysis is based on results that demonstrate randomization over ties in sign...

We generalize the Antràs and Helpman (2004) model of the international organization of production in order to accommodate varying degrees of contractual frictions. In particular, we allow the degree of contractibility to vary across inputs and countries. A continuum of firms with heterogeneous...