This paper provides a mathematical foundation for independent random matching of a large population, as widely used in the economics literature. We consider both static and dynamic systems with random mutation, partial matching arising from search, and type changes induced by matching. Under...

We develop a projection method that can solve dynamic economic models with a large number of state variables. A distinctive feature of our method is that it operates on the ergodic set realized in equilibrium: we simulate a model, distinguish clusters on simulated series and use the clusters'...

We develop a set of necessary and sufficient conditions for equilibria to be determinate in a class of forward-looking Markov-switching rational expectations models and we develop an algorithm to check these conditions in practice. We use three examples, based on the new-Keynesian model of...

The selection of climate policies should be an exercise in risk management reflecting the many relevant sources of uncertainty. Studies of climate change and its impacts rarely yield consensus on the distribution of exposure, vulnerability, or possible outcomes. Hence policy analysis cannot...

We use a network model of credit risk to measure market expectations of the potential spillovers from a sovereign default. Specifically, we develop an empirical model, based on the recent theoretical literature on contagion in financial networks, and estimate it with data on sovereign credit...

Shareholder valuations are economically and statistically positively correlated with more powerful independent directors, their power gauged by social network power centrality measures. Sudden deaths of powerful independent directors significantly reduce shareholder value, consistent with...

Social and economic networks are ubiquitous, serving as contexts for job search, technology diffusion, the accumulation of human capital and even the formulation of norms and values. The systematic empirical study of network formation - the process by which agents form, maintain and dissolve...

Can we identify the members of a community who are best- placed to diffuse information simply by asking a random sample of individuals? We show that boundedly-rational individuals can, simply by tracking sources of gossip, identify those who are most central in a network according to "diffusion...

A principal reason that losses from catastrophic risks have been increasing over time is that more individuals and firms are locating in harm's way while not taking appropriate protective measures. Several behavioural biases lead decision-makers not to invest in adaptation measures until after...

This paper examines the importance of buyer-supplier relationships, geography and the structure of the production network in firm performance. We develop a simple model where firms can outsource tasks and search for suppliers in different locations. Low search and outsourcing costs lead firms to...