Researchers are rapidly developing new automated techniques to scale political speech on an ideological dimension. Yet, the task has proven difficult across many settings. Political advertisements, in particular, have eluded such efforts. Candidates air relatively few ads, containing limited policy information, and there is little agreement about how to model political speech in the campaign, m...

The emergence of politically driven divisions in online discussion networks has attracted a wealth of literature, but also one which has thus far been largely limited to single country studies. Hence whilst there is good evidence that these networks do divide and fragment into what are often described as “echo chambers”, we know little about the factors which might explain this division or make...