Fifteen years after German reunification, the facts about slow regional convergence have born out the prediction of Barro (1991), except that migration out of East Germany has not slowed down. I document that in particular the 18-29 year old are leaving East Germany, and that the emigration has...

We seek to determine the causes and magnitudes of network externalities for the automated clearinghouse (ACH) electronic payments system. We construct an equilibrium model of customer and bank adoption of ACH. We structurally estimate the parameters of the model using an indirect inference...

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...

We argue that the input-output network of investment goods across sectors is an important propagation mechanism for understanding business cycles. First, we show that the empirical network is dominated by a few “investment hubs” that produce the majority of investment goods, are highly...

We develop a heterogeneous-agents network-based model to analyze alternative policies during a pandemic outbreak, accounting for health and economic trade-offs within the same empirical framework. We leverage a variety of data sources, including data on individuals' mobility and encounters...

Celebrity endorsements are often sought to influence public opinion. We ask whether celebrity endorsement per se has an effect beyond the fact that their statements are seen by many, and whether on net their statements actually lead people to change their beliefs. To do so, we conducted a...

Using staggered entry of two dockless bikesharing firms, we find the entrant expands the market for the incumbent. The entry helps the incumbent to serve a greater number of trips, make more bike investment, achieve higher revenue per trip, improve bike utilization rate, and form a wider and...

In order to induce farmers to adopt a productive new agricultural technology, we apply simple and complex contagion diffusion models on rich social network data from 200 villages in Malawi to identify seed farmers to target and train on the new technology. A randomized controlled trial compares...

This paper studies how changes in deportation fear induced by the roll-out of Secure Communities (SC), a far-reaching immigration enforcement program, affected the demand for safety net programs in the United States. We estimate the spillover effect of SC on the take-up of federal means-tested...

Tax enforcement may affect both the behavior of those directly treated and of some taxpayers not directly treated but linked via a network to those who are treated. A large-scale randomized field experiment enables us to examine both the direct and network effects of letters and in-person visits...