This paper seeks to analyze the nature of the terrorist threat following 9/11, and to explore the implications for defense R&D policy. First it reviews the defining trends of defense R&D since the cold war, and brings in pertinent empirical evidence: The US accumulated during the 1990s a defense...

We show how uncertainty shapes the asset allocation, composition, productivity, and value of capital-intensive firms. We do so using detailed, near-universal data on shipping firms' new orders, secondary-market transactions, and demolition of ships. Firms curtail both the acquisition and...

A pervasive problem in the literature on the health costs of pollution is that optimizing individuals may compensate for increases in pollution by reducing their exposure to protect their health. This implies that estimates of the health effects of pollution may vastly understate the full...

There were substantial fluctuations in the numbers of American overseas travelers, especially before World War II. These fluctuations in travel around the robust, long term upward trend are the focus of this paper. We first identify those fluctuations in the raw data and then try to explain the...

In his seminal publications between the 1930s and 1960s, Frederick Lane offered three hypotheses regarding the impact of the Voyages of Discovery that have guided debate ever since. First, pepper and other spice prices did not rise in European markets in the century before the 1490s, and thus...

Using a large, individual-level wage data set, we examine the impact of a major technological innovation the steam engine on skill demand and the wage structure in the merchant shipping industry. We find that the technical change created a new demand for skilled workers, the engineers, while...

I examine the outcomes of cases of entry by merchant shipping lines into established markets around the turn of the century. These established markets are completely dominated by an incumbent cartel composed of several member shipping lines. The cartel makes the decision whether or not to begin...

We study the causal connection between trade and development using one of the earliest massive trade expansions: the first systematic crossing of open seas in the Mediterranean during the time of the Phoenicians. We construct a measure of connectedness along the shores of the sea. This...

Maritime shipping emits as much fine particulate matter as half of global road traffic. We are the first to measure the consequences of US maritime emissions standards on air quality, human health, racial exposure disparities, and behavior. The introduction of US maritime emissions control areas...