Enumeration count of within groups using panel data

[stuart dugarte]

I am working with the MARPOR dataset using STATA15.1.

In the dataset there are a number of observations (parties) per country per election date (there are in some cases numerous elections in a given year). I wish to use the count of elections within a certain country as opposed to the election date itself to structure the panel of my data. i.e. instead of using the election date, I wish to create a running count of elections: for example the first election to take place in Spain in the timeframe of my data would have value "1" and the value for each election would increase by one.

Below is an example of some of the coding attempts I have tried. I hope to not have to count the elections per country manually.

 egen ecount=rank(edate), by(country)

 sort country year
egen id=group(country)
by id date: gen ecount=_n, by(country)

The rank command gives me values for ecount that are unclear. The value for count relying on _n just give me the total number of observations per country.

[Nick Cox]

MARPOR dataset: really isn't self-explanatory. Not giving example data reduces enormously the chance of a useful reply. Please do read and act on the FAQ advice #12.

[stuart dugarte]

Apologies. Here is sample data using dataex.

* Example generated by -dataex-. To install: ssc install dataex
clear
input int country float(edate year) long party
11 -1192 1956 11810
11 -1192 1956 11420
11 -1192 1956 11620
11 -1192 1956 11320
11 -1192 1956 11220
11  -579 1958 11320
11  -579 1958 11220
11  -579 1958 11420
11  -579 1958 11810
11  -579 1958 11620
11   261 1960 11320
11   261 1960 11620
11   261 1960 11220
11   261 1960 11810
11   261 1960 11420
11  1724 1964 11220
11  1724 1964 11620
11  1724 1964 11810
11  1724 1964 11320
11  1724 1964 11420
11  3180 1968 11420
11  3180 1968 11220
11  3180 1968 11810
11  3180 1968 11620
11  3180 1968 11320
11  3915 1970 11620
11  3915 1970 11320
11  3915 1970 11420
11  3915 1970 11810
11  3915 1970 11220
11  5007 1973 11320
11  5007 1973 11810
11  5007 1973 11620
11  5007 1973 11420
11  5007 1973 11220
11  6106 1976 11810
11  6106 1976 11220
11  6106 1976 11420
11  6106 1976 11320
11  6106 1976 11620
11  7198 1979 11320
11  7198 1979 11810
11  7198 1979 11620
11  7198 1979 11220
11  7198 1979 11420
11  8297 1982 11620
11  8297 1982 11220
11  8297 1982 11420
11  8297 1982 11810
11  8297 1982 11320
11  9389 1985 11420
11  9389 1985 11520
11  9389 1985 11220
11  9389 1985 11320
11  9389 1985 11620
11  9389 1985 11810
11 10488 1988 11220
11 10488 1988 11810
11 10488 1988 11620
11 10488 1988 11110
11 10488 1988 11420
11 10488 1988 11320
11 11580 1991 11110
11 11580 1991 11320
11 11580 1991 11951
11 11580 1991 11520
11 11580 1991 11420
11 11580 1991 11810
11 11580 1991 11620
11 11580 1991 11220
11 12679 1994 11420
11 12679 1994 11110
11 12679 1994 11520
11 12679 1994 11320
11 12679 1994 11810
11 12679 1994 11620
11 12679 1994 11220
11 14143 1998 11810
11 14143 1998 11320
11 14143 1998 11220
11 14143 1998 11620
11 14143 1998 11110
11 14143 1998 11520
11 14143 1998 11420
11 15598 2002 11810
11 15598 2002 11520
11 15598 2002 11320
11 15598 2002 11220
11 15598 2002 11420
11 15598 2002 11110
11 15598 2002 11620
11 17061 2006 11810
11 17061 2006 11320
11 17061 2006 11420
11 17061 2006 11220
11 17061 2006 11520
11 17061 2006 11620
11 17061 2006 11110
11 18524 2010 11620
11 18524 2010 11420
11 18524 2010 11710
11 18524 2010 11810
11 18524 2010 11320
11 18524 2010 11520
11 18524 2010 11110
11 18524 2010 11220
11 19980 2014 11620
11 19980 2014 11810
11 19980 2014 11710
11 19980 2014 11220
11 19980 2014 11420
11 19980 2014 11520
11 19980 2014 11110
11 19980 2014 11320
12 -2272 1953 12620
12 -2272 1953 12810
12 -2272 1953 12520
12 -2272 1953 12220
12 -2272 1953 12320
12 -2272 1953 12420
12  -816 1957 12520
12  -816 1957 12220
12  -816 1957 12420
12  -816 1957 12810
12  -816 1957 12620
12  -816 1957 12320
12   619 1961 12221
12   619 1961 12810
12   619 1961 12520
12   619 1961 12320
12   619 1961 12420
12   619 1961 12620
12  2081 1965 12221
12  2081 1965 12320
12  2081 1965 12810
12  2081 1965 12620
12  2081 1965 12420
12  2081 1965 12520
12  3537 1969 12420
12  3537 1969 12320
12  3537 1969 12221
12  3537 1969 12620
12  3537 1969 12520
12  3537 1969 12810
12  5000 1973 12951
12  5000 1973 12221
12  5000 1973 12620
12  5000 1973 12320
12  5000 1973 12410
12  5000 1973 12520
12  5000 1973 12420
12  5000 1973 12810
12  6463 1977 12810
12  6463 1977 12620
12  6463 1977 12420
12  6463 1977 12951
12  6463 1977 12520
12  6463 1977 12320
12  6463 1977 12221
12  7927 1981 12221
12  7927 1981 12951
12  7927 1981 12520
12  7927 1981 12420
12  7927 1981 12810
12  7927 1981 12320
12  7927 1981 12620
12  9382 1985 12951
12  9382 1985 12620
12  9382 1985 12520
12  9382 1985 12420
12  9382 1985 12810
12  9382 1985 12221
12  9382 1985 12320
12 10846 1989 12620
12 10846 1989 12951
12 10846 1989 12520
12 10846 1989 12320
12 10846 1989 12810
12 10846 1989 12221
12 10846 1989 12420
12 12309 1993 12420
12 12309 1993 12221
12 12309 1993 12810
12 12309 1993 12951
12 12309 1993 12520
12 12309 1993 12320
12 12309 1993 12620
12 13773 1997 12221
12 13773 1997 12520
12 13773 1997 12620
12 13773 1997 12420
12 13773 1997 12951
12 13773 1997 12320
12 13773 1997 12810
12 15228 2001 12520
12 15228 2001 12620
12 15228 2001 12221
12 15228 2001 12810
12 15228 2001 12951
12 15228 2001 12420
12 15228 2001 12320
12 16691 2005 12221
12 16691 2005 12420
12 16691 2005 12810
12 16691 2005 12620
12 16691 2005 12520
12 16691 2005 12951
12 16691 2005 12320
12 18154 2009 12620
12 18154 2009 12320
12 18154 2009 12420
12 18154 2009 12520
12 18154 2009 12951
12 18154 2009 12221
12 18154 2009 12810
13 -2446 1953 13620
13 -2446 1953 13952
13 -2446 1953 13320
13 -2446 1953 13420
13 -2446 1953 13410
13 -2446 1953 13220
13 -2292 1953 13420
13 -2292 1953 13220
13 -2292 1953 13620
13 -2292 1953 13421
13 -2292 1953 13410
13 -2292 1953 13320
13 -2292 1953 13952
13  -962 1957 13952
13  -962 1957 13220
13  -962 1957 13620
13  -962 1957 13420
13  -962 1957 13421
13  -962 1957 13320
13  -962 1957 13410
13   319 1960 13952
13   319 1960 13420
13   319 1960 13620
13   319 1960 13220
13   319 1960 13320
13   319 1960 13230
13   319 1960 13410
13   319 1960 13421
13  1726 1964 13230
13  1726 1964 13620
13  1726 1964 13421
13  1726 1964 13420
13  1726 1964 13952
13  1726 1964 13410
13  1726 1964 13320
13  1726 1964 13220
13  2517 1966 13230
13  2517 1966 13952
13  2517 1966 13421
13  2517 1966 13620
13  2517 1966 13422
13  2517 1966 13220
13  2517 1966 13320
13  2517 1966 13420
13  2517 1966 13410
13  2944 1968 13410
13  2944 1968 13620
13  2944 1968 13230
13  2944 1968 13421
13  2944 1968 13420
13  2944 1968 13320
13  2944 1968 13422
13  2944 1968 13952
13  2944 1968 13220
13  2944 1968 13210
13  4281 1971 13410
13  4281 1971 13520
13  4281 1971 13620
13  4281 1971 13952
13  4281 1971 13320
13  4281 1971 13230
13  4281 1971 13420
13  4281 1971 13220
13  4281 1971 13210
13  5086 1973 13520
13  5086 1973 13410
13  5086 1973 13220
13  5086 1973 13330
13  5086 1973 13620
13  5086 1973 13420
13  5086 1973 13952
13  5086 1973 13320
13  5086 1973 13210
13  5086 1973 13951
13  5086 1973 13230
13  5487 1975 13330
13  5487 1975 13320
13  5487 1975 13620
13  5487 1975 13420
13  5487 1975 13220
13  5487 1975 13952
13  5487 1975 13410
13  5487 1975 13520
13  5487 1975 13210
13  5487 1975 13951
end
format %td edate
label values country countries
label def countries 11 "sweden", modify
label def countries 12 "norway", modify
label def countries 13 "denmark", modify
label values party party
label def party 11110 "swe: Green Ecology Party", modify
label def party 11220 "swe: Left Party", modify
label def party 11320 "swe: Social Democratic Labour Party", modify
label def party 11420 "swe: Liberal People’s Party", modify
label def party 11520 "swe: Christian Democrats", modify
label def party 11620 "swe: Moderate Coalition Party", modify
label def party 11710 "swe: Sweden Democrats", modify
label def party 11810 "swe: Centre Party", modify
label def party 11951 "swe: New Democracy", modify
label def party 12220 "nor: Norwegian Communist Party", modify
label def party 12221 "nor: Socialist Left Party", modify
label def party 12320 "nor: Norwegian Labour Party", modify
label def party 12410 "nor: New People’s Party", modify
label def party 12420 "nor: Liberal Party", modify
label def party 12520 "nor: Christian People’s Party", modify
label def party 12620 "nor: Conservative Party", modify
label def party 12810 "nor: Centre Party", modify
label def party 12951 "nor: Progress Party", modify
label def party 13210 "dnk: Left Socialist Party", modify
label def party 13220 "dnk: Danish Communist Party", modify
label def party 13230 "dnk: Socialist People’s Party", modify
label def party 13320 "dnk: Social Democratic Party", modify
label def party 13330 "dnk: Centre Democrats", modify
label def party 13410 "dnk: Danish Social-Liberal Party", modify
label def party 13420 "dnk: Liberals", modify
label def party 13421 "dnk: Independents’ Party", modify
label def party 13422 "dnk: Liberal Centre", modify
label def party 13520 "dnk: Christian People’s Party", modify
label def party 13620 "dnk: Conservative People’s Party", modify
label def party 13951 "dnk: Progress Party", modify
label def party 13952 "dnk: Justice Party", modify

[Nick Cox]

Thanks for the example. This may help:

bysort country (edate) : gen id  = sum(edate != edate[_n-1])

[stuart dugarte]

Excellent thank you very much. Exactly what I was looking for.