Hi there, We hope that you can join us for the Applied Statistics Workshop this Wednesday, February 2nd when we will be happy to have Patrick Perry from the Statistics and Information Sciences Laboratory here at Harvard. Patrick will be presenting joint work with Patrick Wolfe on directed interaction networks. You will find an abstract and link to the paper below. As always, we will serve a light lunch and the talk will begin around 12:15p. “Point process modeling for directed interaction networks” Patrick Perry and Patrick Wolfe Statistics and Information Sciences Laboratory, Harvard University CGIS K354 (1737 Cambridge St.) Wednesday, February 2nd 12 noon Abstract: Network data often take the form of repeated interactions between senders and receivers tabulated over time. Rather than reducing these data to binary ties, a model is introduced for treating directed interactions as a multivariate point process: a Cox multiplicative intensity model using covariates that depend on the history of the process. Consistency and asymptotic normality are proved for the resulting partial-likelihood-based estimators under suitable regularity conditions, and an efficient fitting procedure is described. Multicast interactions--those involving a single sender but multiple receivers--are treated explicitly. A motivating data example shows the effects of reciprocation and group-level preferences on message sending behavior in a corporate e-mail network. Paper: http://arxiv.org/abs/1011.1703 Cheers, matt. ~~~~~~~~~~~ Matthew Blackwell PhD Candidate Institute for Quantitative Social Science Department of Government Harvard University url: http://people.fas.harvard.edu/~blackwel/