A large and growing share of international trade is carried on airplanes. Air cargo is many times more expensive than maritime transport but arrives in destination markets much faster. We model firms' choice between exporting goods using fast but expensive air cargo and slow but cheap ocean...

We examine two factors that might explain the extent of air traffic delays in the United States: network benefits due to hubbing and congestion externalities. Airline hubs enable passengers to cross-connect to many destinations, thus creating network benefits that increase in the number of...

Purchasing goods from distant locations introduces a significant lag between when a product is shipped and when it arrives. This is problematic for firms facing volatile demand, who must place orders before knowing the resolution of demand uncertainty. We provide a model in which airplanes bring...

Airline transport generates a growing share of global greenhouse gas emissions but as of late 2016, this sector has not faced U.S. fuel economy or emissions regulation. At any point in time, airlines own and lease a set of durable vehicles and have invested in human and physical capital and an...

Several policy makers and economists have proposed the adoption of a carbon tax in the United States. It is widely recognized that such a tax in practice must take the form of a tax on the consumption of energy products such as gasoline. Although a large existing literature examines the...

Airports are some of the largest sources of air pollution in the United States. We demonstrate that daily airport runway congestion contributes significantly to local pollution levels and contemporaneous health of residents living nearby and downwind from airports. Our research design exploits...

This paper compares two possible formats for free trade in the Americas: a system of spokes surrounding a U.S. hub, and a free trade area. The paper identifies the sources of welfare change, and it argues that a country's attitude towards a system depends on whether the arrangement is a...

Numerous recently uncovered cartels operated along the supply chain, with firms at one end facilitating collusion at the other - hub-and-spoke arrangements. These cartels are hard to rationalize because they induce double marginalization and higher costs. We examine Canada's alleged bread cartel...

Entrepôts are hubs that facilitate trade between multiple origins and destinations. We study these entrepôts, the network they form, and their impact on international trade. We document that the trade network is a hub-and-spoke system, where 80% of trade is shipped indirectly--nearly all via...

The Hub-and-Spoke network is a defining feature of the airline industry. This paper is among the first in the literature to introduce an empirical framework for analyzing network competition among airlines. Airlines make market entry decisions and choose flight frequencies in the first stage,...