Dear Maarten,
I understand that Stata doesn't know how I have transformed
but I think I didn't pose my question well.  I will try it
again.  
My understanding of the different "options" in -mfx- is the
following:
When regress y on x, use "eyex" for elasticity of y w.r.t.
x
When regress y on lnx, use "eydx" for elasticity of y
w.r.t. x
When regress lny on x, use "dyex" for elasticity of y
w.r.t. x
When regress lny on lnx, use "dydx" for elasticity of y
w.r.t. x
I suppose, my question should have been posed as: is the
above interpretation correct?  A simple yes/no answer would
suffice.  
Thank you very much,
Nishant 
--- Maarten buis <[email protected]> wrote:
> Nishant:
> Stata doesn't know that you previously logged a variable.
> It just sees
> a column in your dataset that contains numbers, what they
> mean or what
> you've done to it, Stata does not know. 
> HTH,
> Maarten
> 
> --- Nishant Dass <[email protected]> wrote:
> > I would like to be able to make a statement like "a 1%
> > change in lnx results in so many % change in y", so
> which
> > of the following would be correct?
> > 
> >     mfx c, var(lnx) dyex
> > OR
> >     mfx c, var(lnx) dydx
> > 
> > The cause of confusion is whether Stata takes the
> logarithm
> > of a variable or uses an already-"logged" variable in
> > calculating the marginal effects.  (If it simply uses
> > already-"logged" variables, then what is the use of
> options
> > other than "dydx"?)
> 
> 
> -----------------------------------------
> Maarten L. Buis
> Department of Social Research Methodology
> Vrije Universiteit Amsterdam
> Boelelaan 1081
> 1081 HV Amsterdam
> The Netherlands
> 
> visiting adress:
> Buitenveldertselaan 3 (Metropolitan), room Z434
> 
> +31 20 5986715
> 
> http://home.fsw.vu.nl/m.buis/
> -----------------------------------------
> 
> 
> 		
>
___________________________________________________________
> 
> Try the all-new Yahoo! Mail. "The New Version is
> radically easier to use" � The Wall Street Journal 
> http://uk.docs.yahoo.com/nowyoucan.html
> *
> *   For searches and help try:
> *   http://www.stata.com/support/faqs/res/findit.html
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
> 
__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/