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| From | Rekha Varghese <RVarghese@impaqint.com> |
| To | "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |
| Subject | st: RE: RE: Treatment effect not produced when running psmatch2 on STATA 12 |
| Date | Wed, 3 Jul 2013 14:37:01 +0000 |
David,
Thanks. That helped.
I am showing the entire output. Two others in our office, using different datasets, also ran into the same problem, though when one of them tried it on Stata 10 at home it worked. Hence, the question about Stata 12. Since you do not have the same problem with Stata 12, maybe it is something internal to our firm's software.
Reg. statalist etiquette: Will be more careful next time!
Rekha
-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Radwin, David
Sent: Tuesday, July 02, 2013 7:39 PM
To: statalist@hsphsun2.harvard.edu
Subject: st: RE: Treatment effect not produced when running psmatch2 on STATA 12
Rekha,
I don't seem to have the same problem using -psmatch2- in Stata 12. Are you showing the entire output?
The silly example below implies that union membership has a treatment effect on the treated (ATT) of increasing hourly wages by $.89.
Please note that the FAQ asks you to mention authors and locations of user-written programs (-psmatch2- is by Edwin Leuven and Barbara Sianesi and is available from SSC) and not to spell Stata in all capital letters.
David
--
David Radwin
Senior Research Associate
Education Studies Division
RTI International
2150 Shattuck Ave., Suite 800
Berkeley, CA 94704
Phone: 510-665-8274
www.rti.org
. sysuse nlsw88
(NLSW, 1988 extract)
. psmatch2 union age tenure grade south, outcome(wage) logit common
Logistic regression Number of obs = 1866
LR chi2(4) = 79.94
Prob > chi2 = 0.0000
Log likelihood = -1001.027 Pseudo R2 = 0.0384
------------------------------------------------------------------------------
union | Coef. Std. Err. z P>|z| [95% Conf. Interval]
-------------+----------------------------------------------------------
-------------+------
age | .0033413 .018228 0.18 0.855 -.0323849 .0390676
tenure | .0471613 .0093689 5.03 0.000 .0287986 .0655241
grade | .063582 .0221642 2.87 0.004 .0201409 .1070231
south | -.6947927 .1166248 -5.96 0.000 -.9233732 -.4662123
_cons | -2.16279 .7826216 -2.76 0.006 -3.6967 -.6288799
------------------------------------------------------------------------------
There are observations with identical propensity score values.
The sort order of the data could affect your results.
Make sure that the sort order is random before calling psmatch2.
----------------------------------------------------------------------------------------
Variable Sample | Treated Controls Difference S.E. T-stat
----------------------------+-------------------------------------------
----------------------------+----------------
wage Unmatched | 8.68811142 7.22912785 1.45898357 .22164775 6.58
ATT | 8.68626376 7.80088291 .88538085 .302022285 2.93
----------------------------+-------------------------------------------
----------------------------+----------------
Note: S.E. does not take into account that the propensity score is estimated.
psmatch2: | psmatch2: Common
Treatment | support
assignment | Off suppo On suppor | Total
-----------+----------------------+----------
Untreated | 0 1,407 | 1,407
Treated | 2 457 | 459
-----------+----------------------+----------
Total | 2 1,864 | 1,866
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-
> statalist@hsphsun2.harvard.edu] On Behalf Of Rekha Varghese
> Sent: Tuesday, July 02, 2013 2:28 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: st: Treatment effect not produced when running psmatch2 on
> STATA
> 12
>
> Hi,
>
> When I used psamtch2 on STATA 12, I get the logit regression to run.
> But the treatment effect is not automatically generated with it. The
> following is the command and output. Is this a STATA 12 issue? Any
> suggestions on how to get the treatment effects to be produced
> automatically using the
> psmatch2 command? Thanks,
>
>
> psmatch2 cctp_treat bdtot admtot vem voth gov_nonfed for_profit rural
> teach_h ospital percent_medicare percent_medicaid cmi penalty_3025,
> out(fake_outcome1)
> logit common
>
> Logistic regression Number of obs =
> 1537
> LR chi2(12) =
> 49.23
> Prob > chi2 =
> 0.0000
> Log likelihood = -902.02616 Pseudo R2 =
> 0.0266
>
> ----------------------------------------------------------------------
> ----
> ----
> cctp_treat | Coef. Std. Err. z P>|z| [95% Conf.
> Interval]
> -------------+--------------------------------------------------------
> -------------+----
> ----
> bdtot | -.0003375 .0007795 -0.43 0.665 -.0018653
> .0011903
> admtot | .0000136 .0000175 0.78 0.435 -.0000206
> .0000479
> vem | 1.05e-06 3.02e-06 0.35 0.729 -4.88e-06
> 6.97e-06
> voth | -4.83e-08 3.22e-07 -0.15 0.881 -6.78e-07
> 5.82e-07
> gov_nonfed | .0583013 .1816423 0.32 0.748 -.2977111
> .4143137
> for_profit | -.353263 .1662154 -2.13 0.034 -.6790392 -
> .0274868
> rural | -.5794989 .269043 -2.15 0.031 -1.106813 -
> .0521843
> teach_hosp~l | .1910294 .1522697 1.25 0.210 -.1074136
> .4894725
> percent_me~e | .0176805 .0070849 2.50 0.013 .0037944
> .0315666
> percent_me~d | .009975 .007018 1.42 0.155 -.00378
> .02373
> cmi | .5187269 .2819726 1.84 0.066 -.0339292
> 1.071383
> penalty_3025 | .3618394 .1409491 2.57 0.010 .0855842
> .6380947
> _cons | -3.029929 .6463519 -4.69 0.000 -4.296755 -
> 1.763102
> ----------------------------------------------------------------------
> ----
> ----
>
>
> Rekha Varghese
>
>
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