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| From | federico.tedeschi@univr.it |
| To | inggrid <inggrid_ep@yahoo.com> |
| Subject | Re: st: DiD |
| Date | Tue, 29 Mar 2011 14:06:57 +0200 |
> gen post05 = year>2000 > gen treat_post05 = treat*post05 > note: post05 omitted because of collinearity > note: treat_post05 omitted because of collinearity May be "post05" has been omitted because it's always equal to 1, and treat_post05 because it's always equal to "treat". I guess you misspecified the condition of post05 (it shouldn't be "year>2000", but "year>2004" or "year>2005"). Federico * * 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/