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Re: st: Moderated mediation analyses
From
William Buchanan <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: Moderated mediation analyses
Date
Mon, 3 Dec 2012 21:03:12 -0800
Check your syntax again. You're incorrectly referencing the estimate you're interested in. [y]_b[wx1] is what you might be trying to reference, but that estimate does not exist in the first equation [m1].
HTH
Sent from my iPhone
On Dec 3, 2012, at 19:14, "Kim, Isok" <[email protected]> wrote:
> Hello,
>
> I am trying to replicate moderated mediation method (Preacher, Rucker & Hayes, 2007) using the UCLA Stata FAQ, (http://www.ats.ucla.edu/stat/stata/faq/modmed.htm#model5). Similar to my previous inquiry about writing stata codes for mediation analysis, it involves -sureg- and -nlcom-. This time, I'm having trouble calculating conditional indirect effect. Below is my stata code:
>
> //RENAME vars for simplification
> rename CESD y /* dependent variable */
> rename PRD x1 /* independent variable */
> rename GC3E m1 /* mediator variable 1 */
> rename ES w /* moderator variable */
>
> /*-sureg-&-nlcom- methods*/
> set more off
> summarize w
> global m=r(mean)
> global s=r(sd)
> capture generate wx1=w*x1 /* moderator(ES) by IV(PRD) */
> capture generate m1w=m1*w /* Mediator 1(GC3E) by Mod(ES) */
>
> set more off
> sureg (m1 x1 w i.SEX AGE EDU i.UNEMP i.MARSTS i.NATIVITY) ///
> (y x1 w wx1 m1 m1w i.SEX AGE EDU i.UNEMP i.MARSTS i.NATIVITY) if NMV5==1
>
> //Conditional indirect effect via m1 with w
> nlcom ([m1]_b[x1]+($m-$s)*[m1]_b[wx1])*([y]_b[m1]+($m-$s)*[y]_b[m1w]) /*mean - 1sd*/
>
> Everything appears to run without an error until the last -nlcom- command. The error message reads, "[wx1] not found." r(111). Any suggestion or insight into resolving this would again be greatly appreciated!
>
> Best,
> isok
>
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