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Re: st: Matching
From
Sophie Jensen <[email protected]>
To
[email protected]
Subject
Re: st: Matching
Date
Mon, 4 Oct 2010 23:54:37 +0100
Also, Im not sure Im meant to have that many observations... I think I
have too many... my matched sample should have less than a few hundred
observations... would you know why I have so many?
On Mon, Oct 4, 2010 at 11:51 PM, Sophie Jensen <[email protected]> wrote:
> Btw, by neigherst neighbour we mean the most compositionally similar - right?
>
> On Mon, Oct 4, 2010 at 11:51 PM, Sophie Jensen <[email protected]> wrote:
>> how do you ensure random sorting... just sort on some varibale?
>> How do you do area matching... radius matching... do you know
>>
>> Thanks
>>
>> S
>> On Mon, Oct 4, 2010 at 11:50 PM, Sophie Jensen <[email protected]> wrote:
>>> Here's what I've done... how would you interpret that:
>>>
>>> . psmatch2 treatment white fsm male if year>2006, n(1)
>>>
>>> Probit regression Number of obs = 15471
>>> LR chi2(4) = 322.40
>>> Prob > chi2 = 0.0000
>>> Log likelihood = -678.85535 Pseudo R2 = 0.1919
>>>
>>> ------------------------------------------------------------------------------
>>> treatment | Coef. Std. Err. z P>|z| [95% Conf. Interval]
>>> -------------+----------------------------------------------------------------
>>> ewhite | .172414 .1514341 1.14 0.255 -.1243915 .4692194
>>> fsm | 1.650061 .2705032 6.10 0.000 1.119885 2.180238
>>> male | .0000787 .0000105 7.50 0.000 .0000581 .0000992
>>> _cons | .4350676 .8062152 0.54 0.589 -1.145085 2.01522
>>> ------------------------------------------------------------------------------
>>>
>>>
>>> pstest fsm eth_white ks2mn outwage_male
>>>
>>> ----------------------------------------------------------------------------
>>> | Mean %reduct | t-test
>>> Variable Sample | Treated Control %bias |bias| | t p>|t|
>>> ------------------------+----------------------------------+----------------
>>> fsm Unmatched | .32883 .13543 136.0 | 18.34 0.000
>>> Matched | .32883 .328 0.6 99.6 | 0.04 0.968
>>> | |
>>> white Unmatched | .58394 .829 -89.1 | -12.70 0.000
>>> Matched | .58394 .54751 13.2 85.1 | 1.00 0.318
>>> | |
>>> male Unmatched | 28221 24729 92.7 | 11.82 0.000
>>> Matched | 28221 28606 -10.2 89.0 | -0.87 0.387
>>> | |
>>>
>>>
>>>
>>> On Mon, Oct 4, 2010 at 11:35 PM, Santosh Kumar <[email protected]> wrote:
>>>> This is an example of matching with 3 neighbors.
>>>>
>>>> psmatch2 improved, pscore(pscore) outcome(diarr) common caliper(.001)
>>>> neighbor(3)
>>>> 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.
>>>> (4005 missing values generated)
>>>>
>>>> Variable Sample Treated Controls Difference S.E. T-stat
>>>>
>>>> diarr Unmatched .104890901 .125810627 -.020919727 .001373497 -15.23
>>>> ATT .104893374 .110885821 -.005992448 .007151216 -0.84
>>>>
>>>> Note: S.E. for ATT does not take into account that the propensity
>>>> score is estimated.
>>>>
>>>> psmatch2: psmatch2: Common
>>>> Treatment support
>>>> assignment Off suppo On suppor Total
>>>>
>>>> Untreated 0 159,136 159,136
>>>> Treated 2 84,829 84,831
>>>>
>>>> Total 2 243,965 243,967
>>>>
>>>> On Mon, Oct 4, 2010 at 6:28 PM, Sophie Jensen <[email protected]> wrote:
>>>>> Could someone perhaps explain the process of this kind of matching please.
>>>>>
>>>>> Thanks
>>>>>
>>>>> S
>>>>>
>>>>> On Mon, Oct 4, 2010 at 11:26 PM, Sophie Jensen <[email protected]> wrote:
>>>>>> Dear statlisters,
>>>>>>
>>>>>> What is the difference between a 1-1 to match and the nearest
>>>>>> neighbour match in stata. I would like to do a nearest neighbour
>>>>>> match, a 1-1 and then specifiy a distance to match on.
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>> S
>>>>>> *
>>>>>> * 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/
>>>>>>
>>>>>
>>>>> *
>>>>> * 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/
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> Santosh
>>>>
>>>> *
>>>> * 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/
>>>>
>>>
>>
>
*
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