Re: st: Where may search difference in difference sample code?

[醫事室明傑ntu <mingchei@ntu.edu.tw>]

thanks
----- Original Message ----- 
From: "stewart" <c.stewart@londonmet.ac.uk>
To: <statalist@hsphsun2.harvard.edu>
Sent: Wednesday, May 13, 2009 7:19 PM
Subject: Re: st: Where may search difference in difference sample code?


> If there are two time periods the difference-in-differences model is
> simply a cross-sectional regression estimated by OLS. When there are
> multiple periods it becomes a pooled-OLS regression (although it is
> advised to add time period dummy variables). These estimation methods
> can be accessed via the appropriate menus (or code) that are provided as
> standard in STATA. However, it is important to specify the variables in
> the model correctly. A very good treatment of this model is provided in
> chapter 13 of Wooldridge (2006) "Introductory Ecoonometrics A Modern
> Approach" South-Western (4th edition).
>
> Thanks,
>
> Chris
>
> 醫事室明傑ntu wrote:
>
> > Dear statalis :
> > Where may search difference in difference sample code?
> > Because  I need to run that?
> >
> > Thanks
> > Mingchei lin
>
> --
> ===============================
> Dr Chris Stewart,
> Economics Subject Group,
> London Metropolitan Business School,
> London Metropolitan University (City campus),
> 84 Moorgate, London, EC2M 6SQ,
> United Kingdom.
> Tel. 44 (0)20 7320 1651 (x69 1651)
> Fax. 44 (0)20 7320 1585
> e-mail: c.stewart@londonmet.ac.uk
> web.
> http://www.londonmet.ac.uk/lmbs/subjects/economics/staff/chris-stewart.cfm
> ===============================
>
>
> Companies Act 2006 : http://www.londonmet.ac.uk/companyinfo
>
>
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