GARCH volatility models with fixed parameters are too restrictive for long time series due to breaks in the volatility process. Flexible alternatives are Markov-switching GARCH and change-point GARCH models. They require estimation by MCMC methods due to the path dependence problem. An unsolved...

We introduce uncertainty and risk aversion to the study of international environmental agreements. We consider a simple model with identical agents and linear payoffs. We show that a stable treaty with positive action always exists. While uncertainty lowers the action of signatories, we find...

We provide the first empirical application of a new approach proposed by Lee (2007) to estimate peer effects in a linear-in-means model. This approach allows to control for group-level unobservable and to solve the reflection problem. We investigate peer effects in student achievement in...

We study some recent developments and challenges in the empirics of the effects of social networks. We focus in particular on researchers’ ability to make policy recommendations based on a standard linear econometric model. We examine the potential compatibility between this type of...

I present a model of conformism in social networks that incorporates both peer effects and self-selection. I find that equilibrium behaviors are linked through the Laplacian matrix of the equilibrium network. I show that conformism has positive social value and that social welfare can be bounded...