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| From | Sorada Tapsuwan <sorada_tapsuwan@hotmail.com> |
| To | STATA-FORUM <statalist@hsphsun2.harvard.edu> |
| Subject | st: mixlogit log normal distribution restriction problems |
| Date | Fri, 26 Feb 2010 14:34:36 +0700 |
Hi I'm trying to estimate a mixlogit model and restrict a number of random variables to follow a lognormal distribution using the command ln(#). However, when I ran the model it gave me an error message that says "Variables specified to have log-normally distributed coefficients should have positive coefficients in the conditional logit model. Try multiplying the variable by -1." I have about 4 variables that have -ve coefficient values in the clogit model but none of them were significantly different from zero, so it's not like the coefficient is definitely -ve. So I figured that if I try to estimate them using mixlogit and restrict them to follow a lognormal distribution they should be okay but STATA doesn't like it. How can I then restrict these 4 variables to follow a lognormal distribution then? Would anyone be able to help me with this problem. How can I overcome this constraint? Thanks S _________________________________________________________________ Hotmail: Trusted email with Microsoft�s powerful SPAM protection. https://signup.live.com/signup.aspx?id=60969 * * 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/