Reshape on month and year simultaneously

[Anne Todd]

I have data for each month of the year across about 2 decades, but it is currently in wide format, where the end of each variable name is YEAR_MONTH, as you can see in the example below. How can I simultaneously reshape on both month and year together, so that the final dataset ends up in month-year observations (12 rows per year, across all 20ish years).

* Example generated by -dataex-. For more info, type help dataex
clear
input byte(STATUS_1992_01 STATUS_1992_02 STATUS_1992_03 STATUS_1992_04 STATUS_1992_05 STATUS_1992_06) int resp_id
1 1 1 -4 -4 -4  1
-4 -4 -4 -4 -4 -4  2
-4 -4 -4 -4 -4 -4  3
-4 -4 -4 -4 -4 -4  4
-4 1 1 1 1 1  5
-4 -4 -4 -4 -4 -4  6
-4 -4 -4 -4 -4 -4  7
-4 -4 -4 -4 -4 -4  8
-4 -4 -4 -4 -4 -4  9
-4 -4 -4 -4 -4 -4 10
end

[Nick Cox]

clear
input byte(STATUS_1992_01 STATUS_1992_02 STATUS_1992_03 STATUS_1992_04 STATUS_1992_05 STATUS_1992_06) int resp_id
1 1 1 -4 -4 -4  1
-4 -4 -4 -4 -4 -4  2
-4 -4 -4 -4 -4 -4  3
-4 -4 -4 -4 -4 -4  4
-4 1 1 1 1 1  5
-4 -4 -4 -4 -4 -4  6
-4 -4 -4 -4 -4 -4  7
-4 -4 -4 -4 -4 -4  8
-4 -4 -4 -4 -4 -4  9
-4 -4 -4 -4 -4 -4 10
end

reshape long STATUS_, i(resp_id) j(sdate) string 

gen mdate = monthly(sdate, "YM")

list, sepby(resp_id)

     +-------------------------------------+
     | resp_id     sdate   STATUS_   mdate |
     |-------------------------------------|
  1. |       1   1992_01         1     384 |
  2. |       1   1992_02         1     385 |
  3. |       1   1992_03         1     386 |
  4. |       1   1992_04        -4     387 |
  5. |       1   1992_05        -4     388 |
  6. |       1   1992_06        -4     389 |
     |-------------------------------------|
  7. |       2   1992_01        -4     384 |
  8. |       2   1992_02        -4     385 |
  9. |       2   1992_03        -4     386 |
 10. |       2   1992_04        -4     387 |
 11. |       2   1992_05        -4     388 |
 12. |       2   1992_06        -4     389 |
     |-------------------------------------|
 13. |       3   1992_01        -4     384 |
 14. |       3   1992_02        -4     385 |
 15. |       3   1992_03        -4     386 |
 16. |       3   1992_04        -4     387 |
 17. |       3   1992_05        -4     388 |
 18. |       3   1992_06        -4     389 |
     |-------------------------------------|
 19. |       4   1992_01        -4     384 |
 20. |       4   1992_02        -4     385 |
 21. |       4   1992_03        -4     386 |
 22. |       4   1992_04        -4     387 |
 23. |       4   1992_05        -4     388 |
 24. |       4   1992_06        -4     389 |
     |-------------------------------------|
 25. |       5   1992_01        -4     384 |
 26. |       5   1992_02         1     385 |
 27. |       5   1992_03         1     386 |
 28. |       5   1992_04         1     387 |
 29. |       5   1992_05         1     388 |
 30. |       5   1992_06         1     389 |
     |-------------------------------------|
 31. |       6   1992_01        -4     384 |
 32. |       6   1992_02        -4     385 |
 33. |       6   1992_03        -4     386 |
 34. |       6   1992_04        -4     387 |
 35. |       6   1992_05        -4     388 |
 36. |       6   1992_06        -4     389 |
     |-------------------------------------|
 37. |       7   1992_01        -4     384 |
 38. |       7   1992_02        -4     385 |
 39. |       7   1992_03        -4     386 |
 40. |       7   1992_04        -4     387 |
 41. |       7   1992_05        -4     388 |
 42. |       7   1992_06        -4     389 |
     |-------------------------------------|
 43. |       8   1992_01        -4     384 |
 44. |       8   1992_02        -4     385 |
 45. |       8   1992_03        -4     386 |
 46. |       8   1992_04        -4     387 |
 47. |       8   1992_05        -4     388 |
 48. |       8   1992_06        -4     389 |
     |-------------------------------------|
 49. |       9   1992_01        -4     384 |
 50. |       9   1992_02        -4     385 |
 51. |       9   1992_03        -4     386 |
 52. |       9   1992_04        -4     387 |
 53. |       9   1992_05        -4     388 |
 54. |       9   1992_06        -4     389 |
     |-------------------------------------|
 55. |      10   1992_01        -4     384 |
 56. |      10   1992_02        -4     385 |
 57. |      10   1992_03        -4     386 |
 58. |      10   1992_04        -4     387 |
 59. |      10   1992_05        -4     388 |
 60. |      10   1992_06        -4     389 |
     +-------------------------------------+

Follow with some variant on

format mdate %tm