st: When to use Log (1+x) Transformation?

["Song" <raravise@gmail.com>]

Dear Stata users,

I need to use log transformation before regression analysis. Because some of 
my variables contain 0, I need to use log (1+x) instead of log (x), where x 
contains only positive values. My question is... Do I need to use log (1+x) 
if x does not contain 0, but contains values less than one? I think I can 
use log (x) in this case.

Thank you for your help.

Reo. 
*
*   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/