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Review
. 2000 Dec;1(4):173-81.
doi: 10.1023/a:1026595011371.

Equivalence of the mediation, confounding and suppression effect

D P MacKinnon  1 , J L Krull, C M Lockwood
Affiliations
Review

Equivalence of the mediation, confounding and suppression effect

D P MacKinnon et al. Prev Sci. 2000 Dec.

Abstract

This paper describes the statistical similarities among mediation, confounding, and suppression. Each is quantified by measuring the change in the relationship between an independent and a dependent variable after adding a third variable to the analysis. Mediation and confounding are identical statistically and can be distinguished only on conceptual grounds. Methods to determine the confidence intervals for confounding and suppression effects are proposed based on methods developed for mediated effects. Although the statistical estimation of effects and standard errors is the same, there are important conceptual differences among the three types of effects.

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Figures

Fig. 1
Fig. 1
A three-variable mediation model.
See this image and copyright information in PMC

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