. Author manuscript; available in PMC: 2021 Feb 1.

Published in final edited form as: Prev Sci. 2020 Feb;21(2):147–157. doi: 10.1007/s11121-019-01076-4

Table 2.

Equivalence between traditional mediation estimators and potential outcomes framework estimators

Traditional Mediation terminology	Potential Outcomes Framework terminology	Estimator
Simple indirect effect in the control group	Pure Natural Indirect Effect (PNIE)	ab
Simple indirect effect in the treatment group	Total Natural Indirect Effect (TNIE)	ab + ah
Simple direct effect at the control group mean of the mediator	Pure Natural Direct Effect (PNDE)	c’ + h i_0m
Simple direct effect at the treatment group mean of the mediator	Total Natural Direct Effect (TNDE)	c’ + h i_0m + ah
Total effect	Total Effect (TE)	c
Interaction term	N/A	h
N/A	Mediated Interaction	ha
N/A	Reference Interaction	h(i_0m−μ_m)