[R-meta] [External] R-sig-meta-analysis Digest, Vol 33, Issue 16

[Cort Rudolph]

Hi,

I did a small simulation study on this once. Including even small numbers of regression coefficients in a MA model will really bias the estimate. https://psyarxiv.com/jacdy/

Cheers,
Cort.

Cort W. Rudolph, Ph.D.
Associate Professor
Industrial and Organizational Psychology
Saint Louis University
Morrissey Hall 2827
St. Louis, MO, 63103
rudolphc using slu.edu 
Office:  +1(314) 977-7299
Mobile: +1(313) 720-7082
www.cortrudolph.com <http://www.cortrudolph.com/>
www.sustainableemployabilitylab.com <http://www.sustainableemployabilitylab.com/>
 

On 2/21/20, 5:03 AM, "R-sig-meta-analysis on behalf of r-sig-meta-analysis-request using r-project.org" <r-sig-meta-analysis-bounces using r-project.org on behalf of r-sig-meta-analysis-request using r-project.org> wrote:

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    Today's Topics:
    
       1. standardized betas transformed to correlation coefficients
          (Yingkai)
       2. Re:  standardized betas transformed to correlation
          coefficients (Viechtbauer, Wolfgang (SP))
    
    ----------------------------------------------------------------------
    
    Message: 1
    Date: Fri, 21 Feb 2020 14:41:41 +0800
    From: Yingkai <yykjiyisuipian using gmail.com>
    To: r-sig-meta-analysis using r-project.org
    Subject: [R-meta] standardized betas transformed to correlation
    	coefficients
    Message-ID:
    	<CAN4zT8H7t6Ps_VcBMNh8YrhB9FyF4czJz1jicjtHyu2wOvfNkg using mail.gmail.com>
    Content-Type: text/plain; charset="utf-8"
    
    Dear all,
    
    I am confused about how to transform standardized betas  to correlation
    coefficients.
    Can I used the simple imputation formula proposed by Peterson and Brown
    (2005) where r = β + 0.05 λ ?  λ is an indicator variable that equals 1
    when β is nonnegative and 0 when β is negative. Is this correct? or
    acceptable ?
    
    
    best,
    -- 
    Yingkai, Ph.D Candidate
    Southwest University, ChongQing, CHINA.
    
    	[[alternative HTML version deleted]]
    
    
    
    
    ------------------------------
    
    Message: 2
    Date: Fri, 21 Feb 2020 08:36:15 +0000
    From: "Viechtbauer, Wolfgang (SP)"
    	<wolfgang.viechtbauer using maastrichtuniversity.nl>
    To: Yingkai <yykjiyisuipian using gmail.com>,
    	"r-sig-meta-analysis using r-project.org"
    	<r-sig-meta-analysis using r-project.org>
    Subject: Re: [R-meta]  standardized betas transformed to correlation
    	coefficients
    Message-ID: <4a2254ab2c754542b161b14598ca06cb using UM-MAIL3213.unimaas.nl>
    Content-Type: text/plain; charset="utf-8"
    
    Dear Yingkai,
    
    I would strongly caution against using this formula. It was empirically derived and has no proper statistical grounding. In general, one cannot transform a standardized regression coefficient into a correlation coefficient (without any further information about how the x and y variables of interest correlate with all of the other predictors in the model). The one exception is the case where there are are no other predictors in the model, in which case the standardized regression coefficient is exactly equal to the correlation coefficient (and which illustrates that at least in this scenario, the transformation equation would be incorrect as it would incorrectly inflate the 'estimated correlation' when the association is positive).
    
    Best,
    Wolfgang
    
    -----Original Message-----
    From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On Behalf Of Yingkai
    Sent: Friday, 21 February, 2020 7:42
    To: r-sig-meta-analysis using r-project.org
    Subject: [R-meta] standardized betas transformed to correlation coefficients
    
    Dear all,
    
    I am confused about how to transform standardized betas  to correlation
    coefficients.
    Can I used the simple imputation formula proposed by Peterson and Brown
    (2005) where r = β + 0.05 λ ?  λ is an indicator variable that equals 1
    when β is nonnegative and 0 when β is negative. Is this correct? or
    acceptable ?
    
    best,
    -- 
    Yingkai, Ph.D Candidate
    Southwest University, ChongQing, CHINA.
    
    
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    End of R-sig-meta-analysis Digest, Vol 33, Issue 16
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