Sobel test of mediation using R

                
                
sobel {multilevel}
Estimate Sobel's (1982) indirect test for mediation. The function provides an estimate of the magnitude of the indirect effect, Sobel's first-order estimate of the standard error associated with the indirect effect, and the corresponding z-value. The estimates are based upon three models as detailed on page 84 of MacKinnon, Lockwood, Hoffman, West and Sheets (2002).
mediation.test {bda}
To compute statistics and p-values for the Sobel test. Results for three versions of “Sobel test” are provided: Sobel test, Aroian test and Goodman test.
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"Sobel test of mediation"
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require(multilevel)
require(bda)
                
                
data(bh1996)
#A small but significant indirect effect indicates leadership mediates
#the relationship between work hours and well-being.
#　sobel(pred,med,out)
sobel(bh1996$HRS,bh1996$LEAD,bh1996$WBEING)
# mediation.test(mv,iv,dv)
mediation.test(bh1996$LEAD,bh1996$HRS, bh1996$WBEING)