\begin{Schunk}
\begin{Sinput}
 anova(mediat.out.0, mediat.out.1)
\end{Sinput}
\begin{Soutput}
Chi Square Difference Test

             Df    AIC    BIC   Chisq Chisq diff Df diff Pr(>Chisq)   
mediat.out.1  3 3124.9 3168.3  2.6647                                 
mediat.out.0  4 3131.9 3171.3 11.6040     8.9393       1   0.002791 **
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
\end{Soutput}
\end{Schunk}
