i am conducting a multilevel analysis using MLA (a free multilevel analysis software by Busing et al.). My model is a random-intercept model, with fixed effects at the individual level and second-level explanatory variables to explain the random variance in the intercept.
I would like to obtain the standardized coefficients of the individual level variables and of the explanatory variables for the random intercept.
I have two urgent questions and I would be happy if someone could give me a hint as to their answer.
Since this program does not automatically provide standardized coefficients of regression coefficients, it is necessary to do this manually. Hox (2002) and others recommend simply re-running the model using standardized variables. But should I enter only the standardized explanatory variables or the outcome variable as well? Unfortunately the literature I found was not precise on this subject.
Also, I could not find any clear references about the effects that standardizing the input variables has on the the estimation of a random intercept with explanatory second-level variables. Literature only mentions that random effects are sensitive to standardization, does this apply to the random intercept as well?
Thank you for your time in advance! Regards, Paul Ringler