Publications (18)
A novel decomposition to explain heterogeneity in observational and randomized studies of causality
Brian Gilbert, Ivan Dıaz, Kara E. Rudolph +2
This paper introduces a novel decomposition framework to explain heterogeneity in causal effects observed across different studies, considering both observational and randomized se…
Identification and estimation of mediational effects of longitudinal modified treatment policies
Brian Gilbert, Katherine L. Hoffman, Nicholas Williams +3
We demonstrate a comprehensive semiparametric approach to causal mediation analysis, addressing the complexities inherent in settings with longitudinal and continuous treatments, c…
Studying continuous, time-varying, and/or complex exposures using longitudinal modified treatment policies
Katherine L. Hoffman, Diego Salazar-Barreto, Nicholas Williams +2
This tutorial discusses methodology for causal inference using longitudinal modified treatment policies. This method facilitates the mathematical formalization, identification, and…
Recanting twins: addressing intermediate confounding in mediation analysis
Tat-Thang Vo, Nicholas Williams, Richard Liu +2
The presence of intermediate confounders, also called recanting witnesses, is a fundamental challenge to the investigation of causal mechanisms in mediation analysis, preventing th…
Nonparametric estimators of interventional (transported) direct and indirect effects that accommodate multiple mediators and multiple intermediate confounders
Kara E Rudolph, Nicholas Williams, Ivan Diaz
Mediation analysis is appealing for its ability to improve understanding of the mechanistic drivers of causal effects, but real-world data complexities challenge its successful imp…
Everything all at once: On choosing an estimand for multi-component environmental exposures
Kara E. Rudolph, Shodai Inose, Nicholas Williams +4
Many research questions -- particularly those in environmental health -- do not involve binary exposures. In environmental epidemiology, this includes multivariate exposure mixture…