Today's speaker: Jamie Robins (T.H. Chan SPH), “Causal Mediation Analysis and The Philosophy of Causation”
Abstract: I introduce an interventionist view of mediation analysis that, unlike standard non-interventionist mediation analysis of Pearl and Vanderweele, (i) does not assume that the mediator has well defined causal effects and/or counterfactuals , (ii) preserves the dictum “ no causation without manipulation” (iii) renders questions of mediation scientific, because eventually testable, (iv) replaces the current complex definitions of path specific effects as nested counterfactuals with easily understood definitions in terms of concrete experimental interventions, (v) facilitates communication with subject matter experts (vi) makes concrete the concept of a “recanting witness” and makes testable the hypothesis that a particular variable is a ‘recanting witness’, (vii) when identified from data, the identifying formulae under an interventionist view and the non-interventionist view are identical; however the effect being identified differs. This talk is based on a joint paper with Ilya Shpitser and Thomas Richardson that generalizes an earlier paper by myself and Thomas Richardson.
The Applied Statistics Workshop (Gov 3009) meets all academic year, Wednesdays, 12pm-1:30pm, in CGIS K354. This workshop is a forum for advanced graduate students, faculty, and visiting scholars to present and discuss methodological or empirical work in progress in an interdisciplinary setting. The workshop features a tour of Harvard's statistical innovations and applications with weekly stops in different fields and disciplines and includes occasional presentations by invited speakers. Free lunch is provided.
More information is available at the Gov 3009 website: https://projects.iq.harvard.edu/applied.stats.workshop-gov3009