Event history models have become a dominant method of analysis in the study of international relations. Conventional event history models, however, retain the assumption that the effects of the covariates remain proportional to each other throughout the duration of the subject's phase....

The assassination of a political leader is among the highest-profile acts of political violence, and conventional wisdom holds that such events often have substantial political, social, and economic effects on states. We investigate the extent to which the assassination of a head of state...

What should a researcher do when statistical analysis software terminates before completion with a message that the Hessian is not invertible? The standard textbook advice is to respecify the model, but this is another way of saying that the researcher should change the question being asked....

An alternative to the classical mixed model with normal random effects is to use a Dirichlet process to model the random effects. Such models have proven useful in practice, and we have observed a noticeable variance reduction, in the estimation of the fixed effects, when the Dirichlet process...