Dear all,
I have a problem that I do not understand why it is occuring.
I want to merge two data files using an id that is a string variable, however some observations do not get matched even though they have the exact same id in the 2 files (This occurs only for some observations).
Any ideas why I may be having this issue?
Thanks.
I attach an example of my data below (my id here is prov_coun_y which is a combination of the names of the province, county and year
Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input str14 province str36 county int year str45 prov_coun_y str6 month_year
"Anhui" "Anqing"    1980 "AnhuiAnqing1980"    "198011"
"Anhui" "Anqing"    1981 "AnhuiAnqing1981"    "198109"
"Anhui" "Anqing"    1982 "AnhuiAnqing1982"    "198201"
"Anhui" "Anqing"    1983 "AnhuiAnqing1983"    "198309"
"Anhui" "Anqing"    1984 "AnhuiAnqing1984"    "198408"
"Anhui" "Anqing"    1985 "AnhuiAnqing1985"    "198504"
"Anhui" "Anqing"    1986 "AnhuiAnqing1986"    "198603"
"Anhui" "Anqing"    1987 "AnhuiAnqing1987"    "198706"
"Anhui" "Anqing"    1988 "AnhuiAnqing1988"    "198802"
"Anhui" "Anqing"    1989 "AnhuiAnqing1989"    "198906"
"Anhui" "Anqing"    1990 "AnhuiAnqing1990"    "199009"
"Anhui" "Anqing"    1991 "AnhuiAnqing1991"    "199110"
"Anhui" "Anqing"    1992 "AnhuiAnqing1992"    "199208"
"Anhui" "Anqing"    1993 "AnhuiAnqing1993"    "199306"
"Anhui" "Anqing"    1994 "AnhuiAnqing1994"    "199409"
"Anhui" "Anqing"    1995 "AnhuiAnqing1995"    "199503"
"Anhui" "Anqing"    1996 "AnhuiAnqing1996"    "199609"
"Anhui" "Anqing"    1997 "AnhuiAnqing1997"    "199711"
"Anhui" "Anqing"    1998 "AnhuiAnqing1998"    "199806"
"Anhui" "Anqing"    1999 "AnhuiAnqing1999"    "199905"
"Anhui" "Anqing"    2000 "AnhuiAnqing2000"    "200009"
"Anhui" "Bengbu"    1980 "AnhuiBengbu1980"    "198010"
"Anhui" "Bengbu"    1981 "AnhuiBengbu1981"    "198109"
"Anhui" "Bengbu"    1982 "AnhuiBengbu1982"    "198209"
"Anhui" "Bengbu"    1983 "AnhuiBengbu1983"    "198312"
"Anhui" "Bengbu"    1984 "AnhuiBengbu1984"    "198404"
"Anhui" "Bengbu"    1985 "AnhuiBengbu1985"    "198511"
"Anhui" "Bengbu"    1986 "AnhuiBengbu1986"    "198609"
"Anhui" "Bengbu"    1987 "AnhuiBengbu1987"    "198711"
"Anhui" "Bengbu"    1988 "AnhuiBengbu1988"    "198810"
"Anhui" "Bengbu"    1989 "AnhuiBengbu1989"    "198905"
"Anhui" "Bengbu"    1990 "AnhuiBengbu1990"    "199007"
"Anhui" "Bengbu"    1991 "AnhuiBengbu1991"    "199110"
"Anhui" "Bengbu"    1992 "AnhuiBengbu1992"    "199203"
"Anhui" "Bengbu"    1993 "AnhuiBengbu1993"    "199312"
"Anhui" "Bengbu"    1994 "AnhuiBengbu1994"    "199408"
"Anhui" "Bengbu"    1995 "AnhuiBengbu1995"    "199503"
"Anhui" "Bengbu"    1996 "AnhuiBengbu1996"    "199612"
"Anhui" "Bengbu"    1997 "AnhuiBengbu1997"    "199710"
"Anhui" "Bengbu"    1998 "AnhuiBengbu1998"    "199806"
"Anhui" "Bengbu"    1999 "AnhuiBengbu1999"    "199903"
"Anhui" "Bengbu"    2000 "AnhuiBengbu2000"    "200004"
"Anhui" "Boxian"    1980 "AnhuiBoxian1980"    "198004"
"Anhui" "Boxian"    1981 "AnhuiBoxian1981"    "198107"
"Anhui" "Boxian"    1982 "AnhuiBoxian1982"    "198208"
"Anhui" "Boxian"    1983 "AnhuiBoxian1983"    "198310"
"Anhui" "Boxian"    1984 "AnhuiBoxian1984"    "198410"
"Anhui" "Boxian"    1985 "AnhuiBoxian1985"    "198512"
"Anhui" "Boxian"    1986 "AnhuiBoxian1986"    "198610"
"Anhui" "Boxian"    1987 "AnhuiBoxian1987"    "198711"
"Anhui" "Boxian"    1988 "AnhuiBoxian1988"    "198806"
"Anhui" "Boxian"    1989 "AnhuiBoxian1989"    "198907"
"Anhui" "Boxian"    1990 "AnhuiBoxian1990"    "199003"
"Anhui" "Boxian"    1991 "AnhuiBoxian1991"    "199109"
"Anhui" "Boxian"    1992 "AnhuiBoxian1992"    "199211"
"Anhui" "Boxian"    1993 "AnhuiBoxian1993"    "199306"
"Anhui" "Boxian"    1994 "AnhuiBoxian1994"    "199402"
"Anhui" "Boxian"    1995 "AnhuiBoxian1995"    "199507"
"Anhui" "Boxian"    1996 "AnhuiBoxian1996"    "199611"
"Anhui" "Boxian"    1997 "AnhuiBoxian1997"    "199704"
"Anhui" "Boxian"    1998 "AnhuiBoxian1998"    "199803"
"Anhui" "Boxian"    1999 "AnhuiBoxian1999"    "199911"
"Anhui" "Boxian"    2000 "AnhuiBoxian2000"    "200007"
"Anhui" "Changfeng" 1980 "AnhuiChangfeng1980" "198007"
"Anhui" "Changfeng" 1981 "AnhuiChangfeng1981" "198102"
"Anhui" "Changfeng" 1982 "AnhuiChangfeng1982" "198208"
"Anhui" "Changfeng" 1983 "AnhuiChangfeng1983" "198304"
"Anhui" "Changfeng" 1984 "AnhuiChangfeng1984" "198410"
"Anhui" "Changfeng" 1985 "AnhuiChangfeng1985" "198505"
"Anhui" "Changfeng" 1986 "AnhuiChangfeng1986" "198604"
"Anhui" "Changfeng" 1987 "AnhuiChangfeng1987" "198709"
"Anhui" "Changfeng" 1988 "AnhuiChangfeng1988" "198810"
"Anhui" "Changfeng" 1989 "AnhuiChangfeng1989" "198912"
"Anhui" "Changfeng" 1990 "AnhuiChangfeng1990" "199005"
"Anhui" "Changfeng" 1991 "AnhuiChangfeng1991" "199106"
"Anhui" "Changfeng" 1992 "AnhuiChangfeng1992" "199208"
"Anhui" "Changfeng" 1993 "AnhuiChangfeng1993" "199311"
"Anhui" "Changfeng" 1994 "AnhuiChangfeng1994" "199402"
"Anhui" "Changfeng" 1995 "AnhuiChangfeng1995" "199503"
"Anhui" "Changfeng" 1996 "AnhuiChangfeng1996" "199607"
"Anhui" "Changfeng" 1997 "AnhuiChangfeng1997" "199701"
"Anhui" "Changfeng" 1998 "AnhuiChangfeng1998" "199805"
"Anhui" "Changfeng" 1999 "AnhuiChangfeng1999" "199910"
"Anhui" "Changfeng" 2000 "AnhuiChangfeng2000" "200001"
"Anhui" "Chao"      1980 "AnhuiChao1980"      "198005"
"Anhui" "Chao"      1981 "AnhuiChao1981"      "198102"
"Anhui" "Chao"      1982 "AnhuiChao1982"      "198212"
"Anhui" "Chao"      1983 "AnhuiChao1983"      "198305"
"Anhui" "Chao"      1984 "AnhuiChao1984"      "198402"
"Anhui" "Chao"      1985 "AnhuiChao1985"      "198502"
"Anhui" "Chao"      1986 "AnhuiChao1986"      "198608"
"Anhui" "Chao"      1987 "AnhuiChao1987"      "198701"
"Anhui" "Chao"      1988 "AnhuiChao1988"      "198809"
"Anhui" "Chao"      1989 "AnhuiChao1989"      "198910"
"Anhui" "Chao"      1990 "AnhuiChao1990"      "199004"
"Anhui" "Chao"      1991 "AnhuiChao1991"      "199108"
"Anhui" "Chao"      1992 "AnhuiChao1992"      "199205"
"Anhui" "Chao"      1993 "AnhuiChao1993"      "199308"
"Anhui" "Chao"      1994 "AnhuiChao1994"      "199408"
"Anhui" "Chao"      1995 "AnhuiChao1995"      "199511"
end