[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: R: Log of nonpositive numbers

From   ucb_gal <>
Subject   Re: st: R: Log of nonpositive numbers
Date   Sat, 29 Mar 2008 13:59:52 -0700 (PDT)

With regards to the wealth variable, I have a number of cases that are substantially negative (with net worth less than negative $50k).  Would adding a constant as large at 100k be OK?

----- Original Message ----
From: Carlo Lazzaro <>
Sent: Saturday, March 29, 2008 1:45:56 AM
Subject: st: R: Log of nonpositive numbers

Dear Ucb_gal,

a tempative answer might be to add a little constant to your zeros, in order
to make natural log transformation feasible. However, this trick will give
you back <0 values. 

Kind Regards,


-----Messaggio originale-----
[] Per conto di ucb_gal
Inviato: sabato 29 marzo 2008 6.57
Oggetto: st: Log of nonpositive numbers


I've seen this question asked a few other times, but I'm still a little
unclear on what the considerations are in thinking this through.

I'm running logistic regressions with the log of income and wealth as
independent variables.  I've seen this done often enough that I didn't
really think twice about it.  But then I realized that while I don't have a
ton of cases with exact 0 values in either variable, I do have a number of
cases with negative wealth.  And all of these show up as missing now.

Am I mistaken in thinking that I've seen studies that use the log of income
as predictors??


Like movies? Here's a limited-time offer: Blockbuster Total Access for one
month at no cost.
*   For searches and help try:

*   For searches and help try:

Looking for last minute shopping deals?  
Find them fast with Yahoo! Search.
*   For searches and help try:

© Copyright 1996–2023 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index