I build a simple dynamic model of the formation of an international social network of importers and exporters. Firms can only export into markets in which they have a contact. They acquire new contacts both at random, and via their network of existing contacts. This model explains (i) the...

We provide a general framework for the study of cascade effects created by interconnections between sectors, firms or financial institutions. Focusing on a multi sector economy linked through a supply network, we show how structural properties of the supply network determine both whether...

Financial network structure is an important determinant of systemic risk. This paper examines how the U.S. interbank network evolved over a long and important period that included two key events: the founding of the Federal Reserve and the Great Depression. Banks established connections to...

Many economic activities are embedded in networks: sets of agents and the (often) rivalrous relationships connecting them to one another. Input sourcing by firms, interbank lending, scientific research, and job search are four examples, among many, of networked economic activities. Motivated by...

Technological progress builds upon itself, with the expansion of invention in one domain propelling future work in linked fields. Our analysis uses 1.8 million U.S. patents and their citation properties to map the innovation network and its strength. Past innovation network structures are...

This paper presents and structurally estimates a model of endogenous network formation and legislative activity of career-motivated politicians. Employing data on socialization and legislative effort of members of the 105th-110th U.S. Congresses, our model reconciles a set of empirical...