Generating a new variable: the share of female candidates per political party per election year

[Gill Steel]

Dear Stata Forum Users,
I have what will be a basic question for advanced Stata users, for which I apologize.
If anyone could help with the correct syntax, I would be very grateful.
I am trying to create a variable that represents the share of female candidates per political party per election year.
The coding is as follows:
sex 0,1 (0=male, 1=female);
seito_r 1-53 (nominal variable coded 1 - 53 each category is a political party)
year is labeled 1996-2024 for each election year, coded 1-10 (10 elections during this time period)
I am using Stata/SE 18.0
Best regards,
Gill

[CODE]
* Example generated by -dataex-. For more info, type help dataex
clear
input byte sex int year long seito_r
0 1996 30
0 1996 46
0 1996 35
1 1996 10
1 1996 24
0 1996 13
0 1996 38
0 1996 30
0 1996 46
0 1996 35
0 1996 10
1 1996 48
0 1996 24
0 1996 38
0 1996 13
0 1996 30
0 1996 46
0 1996 35
1 1996 10
1 1996 13
0 1996 24
0 1996 38
0 1996 30
0 1996 46
1 1996 10
0 1996 35
0 1996 13
0 1996 24
0 1996 35
0 1996 46
0 1996 30
0 1996 10
0 1996 38
0 1996 13
0 1996 24
0 1996 30
0 1996 46
0 1996 35
1 1996 10
0 1996 13
1 1996 24
0 1996 38
0 1996 22

[Andrew Musau]

You can exploit the fact that the mean of a 0/1 variable is a proportion.

* Example generated by -dataex-. For more info, type help dataex
clear
input byte sex int year long seito_r
0 1996 30
0 1996 46
0 1996 35
1 1996 10
1 1996 24
0 1996 13
0 1996 38
0 1996 30
0 1996 46
0 1996 35
0 1996 10
1 1996 48
0 1996 24
0 1996 38
0 1996 13
0 1996 30
0 1996 46
0 1996 35
1 1996 10
1 1996 13
0 1996 24
0 1996 38
0 1996 30
0 1996 46
1 1996 10
0 1996 35
0 1996 13
0 1996 24
0 1996 35
0 1996 46
0 1996 30
0 1996 10
0 1996 38
0 1996 13
0 1996 24
0 1996 30
0 1996 46
0 1996 35
1 1996 10
0 1996 13
1 1996 24
0 1996 38
0 1996 22
end

assert inlist(sex, 0, 1)
bys seito_r year: egen wanted= mean(sex)

Res.:

.  l, sepby(seito_r year)

     +---------------------------------+
     | sex   year   seito_r     wanted |
     |---------------------------------|
  1. |   1   1996        10   .6666667 |
  2. |   0   1996        10   .6666667 |
  3. |   1   1996        10   .6666667 |
  4. |   1   1996        10   .6666667 |
  5. |   1   1996        10   .6666667 |
  6. |   0   1996        10   .6666667 |
     |---------------------------------|
  7. |   0   1996        13   .1666667 |
  8. |   0   1996        13   .1666667 |
  9. |   0   1996        13   .1666667 |
 10. |   0   1996        13   .1666667 |
 11. |   0   1996        13   .1666667 |
 12. |   1   1996        13   .1666667 |
     |---------------------------------|
 13. |   0   1996        22          0 |
     |---------------------------------|
 14. |   0   1996        24   .3333333 |
 15. |   0   1996        24   .3333333 |
 16. |   1   1996        24   .3333333 |
 17. |   1   1996        24   .3333333 |
 18. |   0   1996        24   .3333333 |
 19. |   0   1996        24   .3333333 |
     |---------------------------------|
 20. |   0   1996        30          0 |
 21. |   0   1996        30          0 |
 22. |   0   1996        30          0 |
 23. |   0   1996        30          0 |
 24. |   0   1996        30          0 |
 25. |   0   1996        30          0 |
     |---------------------------------|
 26. |   0   1996        35          0 |
 27. |   0   1996        35          0 |
 28. |   0   1996        35          0 |
 29. |   0   1996        35          0 |
 30. |   0   1996        35          0 |
 31. |   0   1996        35          0 |
     |---------------------------------|
 32. |   0   1996        38          0 |
 33. |   0   1996        38          0 |
 34. |   0   1996        38          0 |
 35. |   0   1996        38          0 |
 36. |   0   1996        38          0 |
     |---------------------------------|
 37. |   0   1996        46          0 |
 38. |   0   1996        46          0 |
 39. |   0   1996        46          0 |
 40. |   0   1996        46          0 |
 41. |   0   1996        46          0 |
 42. |   0   1996        46          0 |
     |---------------------------------|
 43. |   1   1996        48          1 |
     +---------------------------------+

[Nick Cox]

a basic question for advanced Stata users, for which I apologize

No need to apologise. The trick here should seem clear once pointed out, but that's the nature of every little trick.

https://journals.sagepub.com/doi/pdf...867X1101100210 is perhaps more of the same kind of thing.

[Gill Steel]

A huge and heartfelt thank you. You might be astonished to find how much time I spent trying to figure this out.
Thank you for the link. I will take a look now.
I really appreciate your time and expertise.
Sincerely,
Gill