Do new accounts of causal mechanisms offer practical advice for process tracing?

When Alexander George and I wrote our 2005 book, Case Studies and Theory Development in the Social Sciences, a central theme was that theories about causal mechanisms, and process tracing analysis of the observable implications of hypothesized causal mechanisms, were central to qualitative case study research. Our emphasis on causal mechanisms was not especially novel at the time, but it ran counter to the preeminent role that Gary King, Robert Keohane, and Sidney Verba devoted to causal effects, and in the intervening years causal mechanisms have gained added attention from social scientists.