Re: st: Re: propensity score

[zeynal karaca <zeynalkaraca@gmail.com>]

While digesting different component of propensity ADO codes, here is
another question on the same subject for which any help is
appreciated:

The research question I am working on is to tease out the differences
in treatment costs between two different insurance holders, say
Insurance A and Insurance B. I am using an administrative data for
this purpose. The process I am running is to select a set of Insurance
A beneficiaries for whom I can get a match from Insurance B
beneficiaries based on observed characteristics, call X1 and X2.

In the first stage, I am running a logit regression to determine
probability of choosing insurance A using X1 and X2 and get the
predicted probability, call Phat. In the second stage, GLS regression,
I am regressing the cost per beneficiaries on X2, X3 and Phat assuming
that the Phat will capture the differences in costs controlling for
other factors. So the naive question I have here is about X2, which
affects both the choice of insurance type during enrollment period as
well as the treatment cost associated with that beneficiary when
comparing two cohorts.

Any suggestions regarding how I should treat X2? Should it be included
in the second stage, GLS regression, of analysis, if so how to
overcome the case where right hand side variables are function of each
other? Are there other issues should I worry about while first running
pscore and then psmathc2?

As always, thanks in advance for any help provided.

Zeynal Karaca


On Tue, May 31, 2011 at 3:02 AM, Maarten Buis <maartenlbuis@gmail.com> wrote:
> On Tue, May 31, 2011 at 8:56 AM, zeynal karaca wrote:
>>  I am currently in process of implementing propensity score algorithm
>>  using STATA 11. While mighty Google can help a lot, however, I believe
>>  the STATA users in this list serve can provide better input. Before beginning
>>  the actual work, I just need to be sure that psmatch2  and pscore are the most
>>  recent ADO codes developed for this purpose. Are there any other ADO files
>>  developed elsewhere? I would appreciate  further guidance and/or suggestions.
>
> Google is fine, but for this question I my first attempt to answer it
> would be to use -findit- in Stata. For example if you type -findit
> propensity- you'll get a list of relevant entries.
>
> -- Maarten
>
> --------------------------
> Maarten L. Buis
> Institut fuer Soziologie
> Universitaet Tuebingen
> Wilhelmstrasse 36
> 72074 Tuebingen
> Germany
>
>
> http://www.maartenbuis.nl
> --------------------------
>
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-- 
Zeynal Karaca, PhD

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