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Re: st: DiD
From
[email protected]
To
[email protected]
Subject
Re: st: DiD
Date
Tue, 29 Mar 2011 17:10:51 +0200
I think that things could work if:
1) "Treatment" is a binary variable equal to 1 for only and all treated people, regardless of year;
2) "Post05" is a binary variable equal to 1 for only and all observations in year 2007, regardless of whether they are treated or not;
3) "treat_post05" is a binary variable equal to 1 for only and all treated people in year 2007 (all non-treated and all obs. in year 2000 are set to 0).
I think point 3 is ok conditioning on the fact that points 1) and 2) are, since you used the command:
>gen treat_post05 = treat*post05
You said:
> treat and post05treat have the same number of 1!
Therefore my guess is that "treat" is equal to 1 (obviously, for treated people) only in year 2007, while it should be also for year 2000.
Federico
> Hi Federico,
>
> I only have data in 2000 and 2007. The reform took place in 2005
> (before and after).
> So, I could not generate year>2004 etc.
> I checked my data. As your speculation, treat and post05treat
> have the same number of 1!
>
> Is there any suggestion how to run a did regression by using two
> different data points?
>
> I couldn't use a RD design, since I can't construct a threshold
> to determine the eligibility.
>
> Many thanks for the help!
>
>
> Best,
> Inggrid
>
>
>
>
> --- On Tue, 3/29/11, [email protected]
> <[email protected]> wrote:
>
> > From: [email protected] <[email protected]>
> > Subject: Re: st: DiD
> > To: "inggrid" <[email protected]>
> > Cc: [email protected], [email protected]
> > Date: Tuesday, March 29, 2011, 7:06 PM
> > > 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
> >
>
>
>
>
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