Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.

# Re: st: Matching

 From Sophie Jensen <[email protected]> To [email protected] Subject Re: st: Matching Date Mon, 4 Oct 2010 23:51:54 +0100

```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/
>>>
>>
>

*
*   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/
```