Creating un-matched pair based on matched pair

[Grace FM]

I am a new stata user, and I encountered a matching problem. Essentially I would like to convert my data from this to the following format . Basically, I want to add the unmatched ones based on the matched pair. Can someone help me with the code? Thank you so much in advance.

[Andrew Musau]

You are new to Stata but not very new. Review FAQ Advice #12 on how to post effectively and #3 https://www.statalist.org/forums/help#adviceextras on our preference for full real names.

clear
input str3 contributor float(receiver date)
"A" 1 2000
"B" 2 2000
"C" 3 2000
end

fillin contributor date receiver
g check=cond(!_fillin, "Y", "N")

Res.:

. sort contributor _fillin

. l, sepby(cont)

     +----------------------------------------------+
     | contri~r   receiver   date   _fillin   check |
     |----------------------------------------------|
  1. |        A          1   2000         0       Y |
  2. |        A          2   2000         1       N |
  3. |        A          3   2000         1       N |
     |----------------------------------------------|
  4. |        B          2   2000         0       Y |
  5. |        B          3   2000         1       N |
  6. |        B          1   2000         1       N |
     |----------------------------------------------|
  7. |        C          3   2000         0       Y |
  8. |        C          2   2000         1       N |
  9. |        C          1   2000         1       N |
     +----------------------------------------------+

[Grace FM]

Thank you so much for your help.

[Grace FM]

You are new to Stata but not very new. Review FAQ Advice #12 on how to post effectively and #3 https://www.statalist.org/forums/help#adviceextras on our preference for full real names.

clear
input str3 contributor float(receiver date)
"A" 1 2000
"B" 2 2000
"C" 3 2000
end

fillin contributor date receiver
g check=cond(!_fillin, "Y", "N")

Res.:

. sort contributor _fillin

. l, sepby(cont)

+----------------------------------------------+
| contri~r receiver date _fillin check |
|----------------------------------------------|
1. | A 1 2000 0 Y |
2. | A 2 2000 1 N |
3. | A 3 2000 1 N |
|----------------------------------------------|
4. | B 2 2000 0 Y |
5. | B 3 2000 1 N |
6. | B 1 2000 1 N |
|----------------------------------------------|
7. | C 3 2000 0 Y |
8. | C 2 2000 1 N |
9. | C 1 2000 1 N |
+----------------------------------------------+

Hi Andrew,

Thank you so much for your post. But that filling does not sort all of my problems. Basically, I do not want all the interactions between contributors and receivers. I want to have, at each of the given dates, all interactions between each contributor to that (those) receivers. How can I achieve that? Can you help me with that?

Thank you so much for your help.

[Grace FM]

I am sorry I did not make that clear. The problem should be changing

contributor	receiver	date
A	1	2000
B	2	2001
C	3	2002

to the following format

contributor	receiver	date	check
A	1	2000	Y
B	1	2000	N
C	1	2000	N
B	2	2001	Y
A	2	2001	N
C	2	2001	N
C	3	2002	Y
B	3	2002	N
A	3	2002	N

How can I achieve this?

[Andrew Musau]

* Example generated by -dataex-. For more info, type help dataex
clear
input str1 contributor byte receiver int date
"A" 1 2000
"B" 2 2001
"C" 3 2002
end

fillin receiver contributor
bys receiver(date): replace date= date[1]
g check= cond(!_fillin, "Y", "N")

Res.:

. l, sepby(date)

     +----------------------------------------------+
     | contri~r   receiver   date   _fillin   check |
     |----------------------------------------------|
  1. |        A          1   2000         0       Y |
  2. |        C          1   2000         1       N |
  3. |        B          1   2000         1       N |
     |----------------------------------------------|
  4. |        B          2   2001         0       Y |
  5. |        A          2   2001         1       N |
  6. |        C          2   2001         1       N |
     |----------------------------------------------|
  7. |        C          3   2002         0       Y |
  8. |        A          3   2002         1       N |
  9. |        B          3   2002         1       N |
     +----------------------------------------------+