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| From | Steven Samuels <sjsamuels@gmail.com> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: DiD |
| Date | Tue, 29 Mar 2011 20:09:12 -0400 |
I apologize. Apparently you do have untreated families; but in your example (real?) data some have no pre-treatment observations. Steve Ingrid: You cannot do a DID design without a control group. The "DID" means "Difference in Differences". So one would compare after-before in the treated and in the control. In your data set you have only the difference in the treatment group. Steve sjsamuels@gmail.com * * 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/