Department of Economics
University College London
NBER Working Papers and Publications
|May 2010||An Empirical Model for Strategic Network Formation|
with Nicholas A. Christakis, James H. Fowler, Guido W. Imbens: w16039
We develop and analyze a tractable empirical model for strategic network formation that can be estimated with data from a single network at a single point in time. We model the network formation as a sequential process where in each period a single randomly selected pair of agents has the opportunity to form a link. Conditional on such an opportunity, a link will be formed if both agents view the link as beneficial to them. They base their decision on their own characateristics, the characteristics of the potential partner, and on features of the current state of the network, such as whether the two potential partners already have friends in common. A key assumption is that agents do not take into account possible future changes to the network. This assumption avoids complications with th...
|February 2009||Optimal Bandwidth Choice for the Regression Discontinuity Estimator|
with Guido Imbens: w14726
We investigate the problem of optimal choice of the smoothing parameter (bandwidth) for the regression discontinuity estimator. We focus on estimation by local linear regression, which was shown to be rate optimal (Porter, 2003). Investigation of an expected-squared-error-loss criterion reveals the need for regularization. We propose an optimal, data dependent, bandwidth choice rule. We illustrate the proposed bandwidth choice using data previously analyzed by Lee (2008), as well as in a simulation study based on this data set. The simulations suggest that the proposed rule performs well.
Published: Review of Economic Studies (2011) doi: 10.1093/restud/rdr043 First published online: November 24, 2011 citation courtesy of