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From | Bo MacInnis <bo@macinnis.org> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Would _sgmediation_ work for dichotomous dependent variable? |
Date | Sun, 01 Aug 2010 14:17:24 -0700 |
The help file of binary_mediation indicates that mediator variables shall be standardized. Is it a recommendation or a requirement? In my current study, unstandardized mediator seem to make more sense than standardized mediator.
Another question on effect size: I am an economist and trained in being interested in marginal effects rather than coefficients in the nonlinear model like logit or probit but I am working on a project for a psychologist. Would the mediational analysis be extended to marginal effect rather than coefficients in the probit model? e.g., the marginal effect of X on Y is mfx_c, the marginal effect of mediator M on Y is mfx_b, and the marginal effect of X on mediator M is mfx_a, would it make sense if I calculate the effect size based on the ratio of these marginal effects, rather than coefficients?
Thank you a bundle to you, Mr. Ender!! Bo At 01:17 PM 8/1/2010, you wrote:
Bo MacInnis <bo@macinnis.org> wrote: Interested in using the wonderful _sgmediation_ command that Phil Ender provided, I wonder if the use of _sgmediation_ is restricted to linear regression with continuous dependent variable. I have a case where the dependent variable is categorical or even dichotomous, and I've been using probit for the main (total effect) for the dichotomous dependent variable. I'd like to use _sgmediation_ for the mediational analysis. ---- -sgmediation- was not meant for models with either binary mediators or binary response variables. I suggest you try -binary_mediation- (findit binary_mediation) which estimation using the product of coefficients approach with all of the variables standardized. The command syntax is very similar to -sgmediation-. -- Phil Ender UCLA Statistical Consulting Group * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/
* * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/