st: Using clogit After psmatch2

["Bob Sutter" <rdsutterjr@gmail.com>]

I want to use clogit after creating a 1:1 nearest neighbor match using
psmatch2. However, I am unsure how to identify the matched treated and
control observations so that I can specify the group(varname) option in
clogit. 
 
For example, in the lowbirth dataset (webuse lowbirth) the variable pairid
is used as the group(varname) option: clogit low lwt smoke ptd,
group(pairid). And the pairid variable is sturctured like this:
 
pairid    low       age       lwt        smoke  ptd       ht         ui
race1    race2    race3

1          0          14        135      0          0          0          0
1          0          0

1          1          14        101      1          1          0          0
0          0          1

2          0          15        98        0          0          0          0
0          1          0

2          1          15        115      0          0          0          1
0          0          1

 

Therefore, my question is: How do I create a variable like pairid after
using psmatch2?

 

Thanks in advance for your time and assistance.

 

Bob

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