How to generate a dummy variable in the dataset as attached in this post?

[Linghui Han]

I want to generate a dummy variable. When the name for the position of "GS" is the same for the position "GOV" in a given province and year, this dummy variable equals one and otherwise it takes the value of zero. Many thanks!

* Example generated by -dataex-. To install: ssc install dataex
clear
input str24 province int year str15 position str32 name str7(starttime    endtime)
"anhui" 1952 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1952 "GOV" "曾希圣" "1952-08" ""       
"anhui" 1953 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1953 "GOV" "曾希圣" "1952-08" ""       
"anhui" 1954 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1954 "GOV" "曾希圣" "1952-08" ""       
"anhui" 1955 "GOV" "曾希圣" "1952-08" "1955-03"
"anhui" 1955 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1955 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1956 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1956 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1957 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1957 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1958 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1958 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1959 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1959 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1960 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1960 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1961 "GS"  "曾希圣" "1952-01" ""       
"anhui" 1961 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1962 "GS"  "李葆华" "1962-02" ""       
"anhui" 1962 "GS"  "曾希圣" "1952-01" "1962-02"
"anhui" 1962 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1963 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1963 "GS"  "李葆华" "1962-02" ""       
"anhui" 1964 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1964 "GS"  "李葆华" "1962-02" ""       
"anhui" 1965 "GS"  "李葆华" "1962-02" ""       
"anhui" 1965 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1966 "GS"  "李葆华" "1962-02" ""       
"anhui" 1966 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1967 "GS"  "李葆华" "1962-02" "1967-01"
"anhui" 1967 "GOV" "黄岩"    "1955-03" ""       
"anhui" 1968 "GOV" "黄岩"    "1955-03" "1968-04"
"anhui" 1968 "GOV" "李德生" "1968-04" ""       
"anhui" 1969 "GOV" "李德生" "1968-04" ""       
"anhui" 1970 "GOV" "李德生" "1968-04" ""       
"anhui" 1971 "GOV" "李德生" "1968-04" ""       
"anhui" 1971 "GS"  "李德生" "1971-01" ""       
"anhui" 1972 "GOV" "李德生" "1968-04" ""       
"anhui" 1972 "GS"  "李德生" "1971-01" ""       
"anhui" 1973 "GOV" "李德生" "1968-04" ""       
"anhui" 1973 "GS"  "李德生" "1971-01" ""       
"anhui" 1974 "GOV" "宋佩璋" "1974-12" ""       
"anhui" 1974 "GS"  "李德生" "1971-01" "1974-12"
"anhui" 1974 "GOV" "李德生" "1968-04" "1974-12"
"anhui" 1975 "GS"  "宋佩璋" "1975-05" ""       
"anhui" 1975 "GOV" "宋佩璋" "1974-12" ""       
"anhui" 1976 "GS"  "宋佩璋" "1975-05" ""       
"anhui" 1976 "GOV" "宋佩璋" "1974-12" ""       
"anhui" 1977 "GOV" "宋佩璋" "1974-12" ""       
"anhui" 1977 "GS"  "宋佩璋" "1975-05" "1977-06"
"anhui" 1977 "GS"  "万里"    "1977-06" ""       
"anhui" 1978 "GOV" "万里"    "1978-01" ""       
"anhui" 1978 "GS"  "万里"    "1977-06" ""       
"anhui" 1978 "GOV" "宋佩璋" "1974-12" "1978-01"
"anhui" 1979 "GS"  "万里"    "1977-06" ""       
"anhui" 1979 "GOV" "万里"    "1978-01" "1979-12"
"anhui" 1979 "GOV" "张劲夫" "1979-12" ""       
"anhui" 1980 "GS"  "万里"    "1977-06" "1980-03"
"anhui" 1980 "GS"  "张劲夫" "1980-03" ""       
"anhui" 1980 "GOV" "张劲夫" "1979-12" ""       
"anhui" 1981 "GS"  "张劲夫" "1980-03" ""       
"anhui" 1981 "GOV" "周子健" "1981-03" ""       
"anhui" 1981 "GOV" "张劲夫" "1979-12" "1981-03"
"anhui" 1982 "GOV" "周子健" "1981-03" ""       
"anhui" 1982 "GS"  "张劲夫" "1980-03" "1982-04"
"anhui" 1982 "GS"  "周子健" "1982-04" ""       
"anhui" 1983 "GS"  "黄璜"    "1983-03" ""       
"anhui" 1983 "GOV" "王郁昭" "1983-04" ""       
"anhui" 1983 "GS"  "周子健" "1982-04" "1983-03"
"anhui" 1983 "GOV" "周子健" "1981-03" "1983-04"
"anhui" 1984 "GS"  "黄璜"    "1983-03" ""       
"anhui" 1984 "GOV" "王郁昭" "1983-04" ""       
"anhui" 1985 "GS"  "黄璜"    "1983-03" ""       
"anhui" 1985 "GOV" "王郁昭" "1983-04" ""       
"anhui" 1986 "GS"  "李贵鲜" "1986-04" ""       
"anhui" 1986 "GOV" "王郁昭" "1983-04" ""       
"anhui" 1986 "GS"  "黄璜"    "1983-03" "1986-04"
"anhui" 1987 "GS"  "李贵鲜" "1986-04" ""       
"anhui" 1987 "GOV" "王郁昭" "1983-04" "1987-06"
"anhui" 1987 "GOV" "卢荣景" "1987-06" ""       
"anhui" 1988 "GS"  "李贵鲜" "1986-04" "1988-04"
"anhui" 1988 "GOV" "卢荣景" "1988-02" ""       
"anhui" 1988 "GOV" "卢荣景" "1987-06" "1988-02"
"anhui" 1988 "GS"  "卢荣景" "1988-04" ""       
"anhui" 1989 "GS"  "卢荣景" "1988-04" ""       
"anhui" 1989 "GOV" "卢荣景" "1988-02" "1989-04"
"anhui" 1989 "GOV" "傅锡寿" "1989-04" ""       
"anhui" 1990 "GS"  "卢荣景" "1988-04" ""       
"anhui" 1990 "GOV" "傅锡寿" "1989-04" ""       
"anhui" 1991 "GS"  "卢荣景" "1988-04" ""       
"anhui" 1991 "GOV" "傅锡寿" "1989-04" ""       
"anhui" 1992 "GOV" "傅锡寿" "1989-04" ""       
"anhui" 1992 "GS"  "卢荣景" "1988-04" ""       
"anhui" 1993 "GS"  "卢荣景" "1988-04" ""       
"anhui" 1993 "GOV" "傅锡寿" "1989-04" ""       
"anhui" 1994 "GOV" "回良玉" "1994-12" ""       
"anhui" 1994 "GS"  "卢荣景" "1988-04" ""       
end

[Linghui Han]

Sorry for that the values of the variable "name" are in Chinese.

[Andrew Musau]

Sorry for that the values of the variable "name" are in Chinese.

Not to worry, the question is understood.

bys province year (name): egen wanted= max(name==name[_n-1] & position!=position[_n-1])

[Linghui Han]

Thank you very much! It works very well.

[Linghui Han]

I have another question regarding the same dataset. I want to calculate how many years for each name serving on each position. But there are observations with the same name on the same position in the same year. How to tease this out? Many thanks!

[Andrew Musau]

This means that you have one or more duplicate observations in your data set. Here is one way to obtain counts in the presence of duplicates.

*CHECK IF VARIABLES UNIQUELY IDENTIFY OBSERVATIONS
isid province year position name
*PICK OUT ONLY ONE OBSERVATION PER VARIABLE COMBINATIONS
 bys province year position name: gen fob=_n==1
*GENERATE RUNNING COUNT
bys province position name (year): gen count= sum(1) if fob & !missing(name)
*GENERATE TOTAL COUNT
bys province position name: egen total= total(1) if fob & !missing(name)

Result:

. l province year position name count total, sepby(province position name)

     +-----------------------------------------------------+
     | province   year   position     name   count   total |
     |-----------------------------------------------------|
  1. |    anhui   1978        GOV     万里       1       2 |
  2. |    anhui   1979        GOV     万里       2       2 |
     |-----------------------------------------------------|
  3. |    anhui   1989        GOV   傅锡寿       1       5 |
  4. |    anhui   1990        GOV   傅锡寿       2       5 |
  5. |    anhui   1991        GOV   傅锡寿       3       5 |
  6. |    anhui   1992        GOV   傅锡寿       4       5 |
  7. |    anhui   1993        GOV   傅锡寿       5       5 |
     |-----------------------------------------------------|
  8. |    anhui   1987        GOV   卢荣景       1       3 |
  9. |    anhui   1988        GOV   卢荣景       .       . |
 10. |    anhui   1988        GOV   卢荣景       2       3 |
 11. |    anhui   1989        GOV   卢荣景       3       3 |
     |-----------------------------------------------------|
 12. |    anhui   1981        GOV   周子健       1       3 |
 13. |    anhui   1982        GOV   周子健       2       3 |
 14. |    anhui   1983        GOV   周子健       3       3 |
     |-----------------------------------------------------|
 15. |    anhui   1994        GOV   回良玉       1       1 |
     |-----------------------------------------------------|
 16. |    anhui   1974        GOV   宋佩璋       1       5 |
 17. |    anhui   1975        GOV   宋佩璋       2       5 |
 18. |    anhui   1976        GOV   宋佩璋       3       5 |
 19. |    anhui   1977        GOV   宋佩璋       4       5 |
 20. |    anhui   1978        GOV   宋佩璋       5       5 |
     |-----------------------------------------------------|
 21. |    anhui   1979        GOV   张劲夫       1       3 |
 22. |    anhui   1980        GOV   张劲夫       2       3 |
 23. |    anhui   1981        GOV   张劲夫       3       3 |
     |-----------------------------------------------------|
 24. |    anhui   1952        GOV   曾希圣       1       4 |
 25. |    anhui   1953        GOV   曾希圣       2       4 |
 26. |    anhui   1954        GOV   曾希圣       3       4 |
 27. |    anhui   1955        GOV   曾希圣       4       4 |
     |-----------------------------------------------------|
 28. |    anhui   1968        GOV   李德生       1       7 |
 29. |    anhui   1969        GOV   李德生       2       7 |
 30. |    anhui   1970        GOV   李德生       3       7 |
 31. |    anhui   1971        GOV   李德生       4       7 |
 32. |    anhui   1972        GOV   李德生       5       7 |
 33. |    anhui   1973        GOV   李德生       6       7 |
 34. |    anhui   1974        GOV   李德生       7       7 |
     |-----------------------------------------------------|
 35. |    anhui   1983        GOV   王郁昭       1       5 |
 36. |    anhui   1984        GOV   王郁昭       2       5 |
 37. |    anhui   1985        GOV   王郁昭       3       5 |
 38. |    anhui   1986        GOV   王郁昭       4       5 |
 39. |    anhui   1987        GOV   王郁昭       5       5 |
     |-----------------------------------------------------|
 40. |    anhui   1955        GOV     黄岩       1      14 |
 41. |    anhui   1956        GOV     黄岩       2      14 |
 42. |    anhui   1957        GOV     黄岩       3      14 |
 43. |    anhui   1958        GOV     黄岩       4      14 |
 44. |    anhui   1959        GOV     黄岩       5      14 |
 45. |    anhui   1960        GOV     黄岩       6      14 |
 46. |    anhui   1961        GOV     黄岩       7      14 |
 47. |    anhui   1962        GOV     黄岩       8      14 |
 48. |    anhui   1963        GOV     黄岩       9      14 |
 49. |    anhui   1964        GOV     黄岩      10      14 |
 50. |    anhui   1965        GOV     黄岩      11      14 |
 51. |    anhui   1966        GOV     黄岩      12      14 |
 52. |    anhui   1967        GOV     黄岩      13      14 |
 53. |    anhui   1968        GOV     黄岩      14      14 |
     |-----------------------------------------------------|
 54. |    anhui   1977         GS     万里       1       4 |
 55. |    anhui   1978         GS     万里       2       4 |
 56. |    anhui   1979         GS     万里       3       4 |
 57. |    anhui   1980         GS     万里       4       4 |
     |-----------------------------------------------------|
 58. |    anhui   1988         GS   卢荣景       1       7 |
 59. |    anhui   1989         GS   卢荣景       2       7 |
 60. |    anhui   1990         GS   卢荣景       3       7 |
 61. |    anhui   1991         GS   卢荣景       4       7 |
 62. |    anhui   1992         GS   卢荣景       5       7 |
 63. |    anhui   1993         GS   卢荣景       6       7 |
 64. |    anhui   1994         GS   卢荣景       7       7 |
     |-----------------------------------------------------|
 65. |    anhui   1982         GS   周子健       1       2 |
 66. |    anhui   1983         GS   周子健       2       2 |
     |-----------------------------------------------------|
 67. |    anhui   1975         GS   宋佩璋       1       3 |
 68. |    anhui   1976         GS   宋佩璋       2       3 |
 69. |    anhui   1977         GS   宋佩璋       3       3 |
     |-----------------------------------------------------|
 70. |    anhui   1980         GS   张劲夫       1       3 |
 71. |    anhui   1981         GS   张劲夫       2       3 |
 72. |    anhui   1982         GS   张劲夫       3       3 |
     |-----------------------------------------------------|
 73. |    anhui   1952         GS   曾希圣       1      11 |
 74. |    anhui   1953         GS   曾希圣       2      11 |
 75. |    anhui   1954         GS   曾希圣       3      11 |
 76. |    anhui   1955         GS   曾希圣       4      11 |
 77. |    anhui   1956         GS   曾希圣       5      11 |
 78. |    anhui   1957         GS   曾希圣       6      11 |
 79. |    anhui   1958         GS   曾希圣       7      11 |
 80. |    anhui   1959         GS   曾希圣       8      11 |
 81. |    anhui   1960         GS   曾希圣       9      11 |
 82. |    anhui   1961         GS   曾希圣      10      11 |
 83. |    anhui   1962         GS   曾希圣      11      11 |
     |-----------------------------------------------------|
 84. |    anhui   1971         GS   李德生       1       4 |
 85. |    anhui   1972         GS   李德生       2       4 |
 86. |    anhui   1973         GS   李德生       3       4 |
 87. |    anhui   1974         GS   李德生       4       4 |
     |-----------------------------------------------------|
 88. |    anhui   1962         GS   李葆华       1       6 |
 89. |    anhui   1963         GS   李葆华       2       6 |
 90. |    anhui   1964         GS   李葆华       3       6 |
 91. |    anhui   1965         GS   李葆华       4       6 |
 92. |    anhui   1966         GS   李葆华       5       6 |
 93. |    anhui   1967         GS   李葆华       6       6 |
     |-----------------------------------------------------|
 94. |    anhui   1986         GS   李贵鲜       1       3 |
 95. |    anhui   1987         GS   李贵鲜       2       3 |
 96. |    anhui   1988         GS   李贵鲜       3       3 |
     |-----------------------------------------------------|
 97. |    anhui   1983         GS     黄璜       1       4 |
 98. |    anhui   1984         GS     黄璜       2       4 |
 99. |    anhui   1985         GS     黄璜       3       4 |
100. |    anhui   1986         GS     黄璜       4       4 |
     +-----------------------------------------------------+

.

[Linghui Han]

It's very clear and helpful for learning. Appreciation!