Indirect effects of multiple mediators

 PLS Junior User
 Posts: 6
 Joined: Mon Apr 12, 2010 1:26 pm
 Real name and title:
Indirect effects of multiple mediators
Dear PLS users,
I am trying to perform a mediation analysis which involves 1 IV, 1 DV, and 3 mediators. I am quite familiar with the 4 steps approach by Baron and Kenny (1986), but I found it quite difficult to calculate the indirect effects through each mediators using PLS.
Please advise.
Many thanks,
Derwin.
I am trying to perform a mediation analysis which involves 1 IV, 1 DV, and 3 mediators. I am quite familiar with the 4 steps approach by Baron and Kenny (1986), but I found it quite difficult to calculate the indirect effects through each mediators using PLS.
Please advise.
Many thanks,
Derwin.

 PLS Junior User
 Posts: 6
 Joined: Mon Apr 12, 2010 1:26 pm
 Real name and title:
Could Bootstrapping work for 3Path Mediated Effect?
Hello everyone,
first of all, one article which I found quite useful for the assessment of multiple mediators is
TAYLOR; MACKINNON; TEIN (2005). Tests of the threepath mediated effect. Organizational Research Methods, 11 (2), p. 241269.
I will draw on their model (p243) to phrase my question more clearly:
exogenous variable: X
two mediators: M1, M2
endogenous variable: Y
X > M1: (path) Beta1
M1 > M2: Beta2
M2 > Y: Beta3
X > Y: Beta4
X > M2: Beta5
M2 > Y: Beta6
Thus the whole mediation consists of (Beta1*Beta2*Beta3) + (Beta1*Beta6) + (Beta5*Beta3). Unfortunately TAYLOR et al. only give hints how best to assess the first term.
If you follow the article Prof. Bibo has quoted, you could assess the other two terms by splitting the model, once leaving out X, once leaving out Y and do the Sobel test.
Later on in my model, I plan to split my sample and do a multigroup analysis. By this means I would like to show, that the moderators work differently each time. Thus it would be useful to have the same tool to compare all the effects.
The idea I came up with was to use the "Bootstrapping the indirect effect"  method (Preacher and Hayes 2008) to calculate the standard deviation and thus to calculate the tvalues
For the 2nd and 3rd term, this would be quite a standard procedure, for the first term, you could calculate
(total effect (x > Y)  indirect effect (calculated for 2nd term)  indirect effect (calculated for 3rd term)  direct effect (X > Y))
Could this work? Has anybody tried it before?
Thank you for your suggestions
first of all, one article which I found quite useful for the assessment of multiple mediators is
TAYLOR; MACKINNON; TEIN (2005). Tests of the threepath mediated effect. Organizational Research Methods, 11 (2), p. 241269.
I will draw on their model (p243) to phrase my question more clearly:
exogenous variable: X
two mediators: M1, M2
endogenous variable: Y
X > M1: (path) Beta1
M1 > M2: Beta2
M2 > Y: Beta3
X > Y: Beta4
X > M2: Beta5
M2 > Y: Beta6
Thus the whole mediation consists of (Beta1*Beta2*Beta3) + (Beta1*Beta6) + (Beta5*Beta3). Unfortunately TAYLOR et al. only give hints how best to assess the first term.
If you follow the article Prof. Bibo has quoted, you could assess the other two terms by splitting the model, once leaving out X, once leaving out Y and do the Sobel test.
Later on in my model, I plan to split my sample and do a multigroup analysis. By this means I would like to show, that the moderators work differently each time. Thus it would be useful to have the same tool to compare all the effects.
The idea I came up with was to use the "Bootstrapping the indirect effect"  method (Preacher and Hayes 2008) to calculate the standard deviation and thus to calculate the tvalues
For the 2nd and 3rd term, this would be quite a standard procedure, for the first term, you could calculate
(total effect (x > Y)  indirect effect (calculated for 2nd term)  indirect effect (calculated for 3rd term)  direct effect (X > Y))
Could this work? Has anybody tried it before?
Thank you for your suggestions
Hope to put it right
It should be easier to calculate the first term by just multiplying each Bootstrap sample (Beta1*Beta2*Beta3) to get the standard deviation!
Re: Indirect effects of multiple mediators
Please, I am a doctoral candidate. i am presently analysing my data. i have 1IV, 2mediators and 1DV and the are all second order constructs(reflectivereflective). What are those things that i need to report in my study starting from missing data? Thanks.
Kayode David
Department of Educational Management
School of Education and Modern Languages
College of Arts and Sciences
University Utara malaysia
Department of Educational Management
School of Education and Modern Languages
College of Arts and Sciences
University Utara malaysia