Hi
I have a question about the analysis of moderating variables: can moderating variables be used as covariates for other variables in the model?
I have 4 variables:
Y is the outcome variable
X is the predictor variable
M is the mediating variable of X-Y
W is the moderator variable of X-M
>>> W is the covariate of Y
I am not sure if W can still be used as an independent variable for Y, given that it has already been used as a moderator variable for X-M (I had hoped that W could still serve as a control variable for X).
I will get an error when running this model in SPSS PROCESS: SINGULAR OR NEAR SINGULAR DATA MATRIX
Although PLS can execute this model, it is uncertain whether there will be errors in principle.