Dear statalist,
I have a list of companies and variables (hereafter) where isin identifies different companies, year and dates. Some companies (same isin) appears different times in the sample. I want to have a difference of more than 180 days if two ccompanies have the same isin. So I want to drop the companies with the same isin when the difference between two dates is less than 180 days I tried the comman bygroup and count but I don't manage to get what I want.
Thank a lot for your answers;
Najiba
I have a list of companies and variables (hereafter) where isin identifies different companies, year and dates. Some companies (same isin) appears different times in the sample. I want to have a difference of more than 180 days if two ccompanies have the same isin. So I want to drop the companies with the same isin when the difference between two dates is less than 180 days I tried the comman bygroup and count but I don't manage to get what I want.
Thank a lot for your answers;
Najiba
Code:
* Example generated by -dataex-. To install: ssc install dataex clear input str28 company int year str14(isin date) "Michelin" 2009 "FR0000121261" " 6/17/2009" "Total" 2009 "FR0000120271" " 3/10/2009" "Accor" 2009 "FR0000120271" " 6/30/2009" "Air France" 2009 "FR0000031122 " " 2/13/2009" "Air France" 2009 "FR0000031122 " " 4/15/2009" "Air France" 2009 "FR0000031122 " " 9/4/2009" "Air Liquide" 2009 "FR0000120073" "10/18/2009" "ARKEMA" 2009 "FR0010313833" "10/22/2009" "Alcaltel Lucent" 2009 "FR0000130007" " 2/11/2009" "Idestylealten" 2009 "FR0000071946" "10/16/2009" "Altran" 2009 "FR0000034639" " 6/18/2009" "Atos" 2009 "FR0000051732" " 2/18/2009" "Beneteau" 2009 "FR0000035164" " 4/2/2009" "Club Med " 2009 "FR0000121568" " 6/26/2009" "Eramet" 2009 "FR0000131757" " 8/5/2009" "FAURECIA SE" 2009 "FR0000121147" " 2/5/2009" "Flo goupe" 2009 "FR0004076891" " 3/6/2009" "France Telecom" 2009 "FR0000133308" " 3/4/2009" "France champi" 2009 "FR0000063935" " 8/27/2009" "Indeix multimed" 2009 "FR0004061513" " 1/23/2009" "3 SUISSE" 2009 "FR0000121485" " 2/11/2009" "OENEO" 2009 "FR0000052680" " 2/5/2009" "L'oréal " 2009 "FR0000120321" " 2/17/2009" "Fnac " 2009 "FR0011476928" " 2/18/2009" "LA RECOUTE" 2009 "FR0000121485" " 10/5/2009" "Manitou" 2009 "FR0000038606" " 4/2/2009" "Latécoère" 2009 "FR0000032278" " 9/16/2009" "LVMH" 2009 "FR0000121014" " 2/6/2009" "Marriaunuad" 2009 "FR0000064941" " 6/15/2009" "nexans" 2009 "FR0000044448 " " 9/18/2009" "NEXTRADIO" 2009 "FR0010240994" " 2/13/3009" "PCAS" 2009 "FR0000053514" " 4/16/2009" "PLASTIVALOIRE" 2009 "FR0000051377" " 3/25/2009" "RHODI" 2009 "FR0010479956" " 3/20/2009" "ROCAMET" 2009 "FR0000064255" " 1/31/2009" "SAINT GOBAIN" 2009 "FR0000125007" " 9/8/2009" "SAFRAN" 2009 "FR0000073272" " 7/9/2009" "SANOFI" 2009 "FR0000120578" " 6/30/2009" "SELECTRIC" 2009 "FR0000121972 " " 1/29/2009" "SEB" 2009 "FR0000121709" " 2/11/2009" "SEQUANA" 2009 "FR0000063364" " 7/27/2009" "SOITEC" 2009 "FR0013227113" " 4/2/2009" "SPIR COMM" 2009 "FR0000131732" " 1/29/2009" "ST DUPONF" 2009 "FR0000054199" " 6/16/2009" "TAHLES" 2009 "FR0000121329 " " 7/1/2009" "teleperfomrance" 2009 "FR0000051807" " 6/16/2009" "VALEO" 2009 "FR0013176526" " 1/15/2009" "VEDIOR" 2009 "FR0000077570" " 1/9/2009" "REDOUTE" 2009 "FR0000121485" " 2/11/2009" "FNAX" 2009 "FR0000121485" " 3/4/2009" "Air Liquide" 2009 "FR0000120073" " 3/27/2009" "Alcaltel Lucent" 2009 "FR0000130007" " 7/1/2009" "ARKEMA" 2009 "FR0010313833 " " 3/11/2009" "ARKEMA" 2009 "FR0010313833 " " 9/1/2009" "ARKEMA" 2009 "FR0010313833 " " 11/6/2009" "Latécoère" 2009 "FR0000032278" " 6/3/2009" "LVMH ZENITH" 2009 "FR0000121014" " 6/12/2009" "VALEO" 2009 "FR0013176526" " 1/16/2009" "VALEO" 2009 "FR0013176526" " 1/10/2009" "VALEO" 2009 "FR0013176526" " 3/3/2009" "BOURBON" 2009 "FR0004548873" " 7/30/2009" "AUGROS" 2009 "FR0000061780" " 1/12/2009" "SAFT" 2009 "FR0010208165" "70CT OU 10SEPT" "EXCEL INDUSTRIE" 2009 "FR0004527638" " 5/1/2009" "HIOLLES" 2009 "FR0000077562" "12/18/2009" "ESPACE PROD" 2009 "FR0004048072" " 5/28/2009" "PONCIN YACHT" 2009 "FR0010193052 " " 8/1/2009" "CHARGEURS" 2009 "FR0000130692 /" " 5/15/2009" "INFOVISTA" 2009 "FR0004031649" " 2/12/2009" "FAURECIA SE" 2009 "FR0000121147" " 2/5/2009" "FRANDCE TELECIM" 2009 "FR0000133308." " 1/15/2009" "RHODIA " 2009 "FR0010479956" " 2/23/2009" "RHODIA " 2009 "FR0010479956" " 3/20/2009" "RHODIA " 2009 "FR0010479956" " 5/6/2009" "overlap" 2009 "FR0010759530" " 5/16/2009" "TOTALENERGIES SE" 2010 "FR0000120271" " 1/21/2010" "NICOX SA" 2010 "FR0013018124" " 12/1/2010" "EVERGREEN SA" 2010 "FR0000035784" " 2/23/2010" "TECHNICOLOR SA" 2010 "FR0013505062" " 3/31/2010" "REMY COINTREAU" 2010 "FR0000130395" " 2/5/2010" "GROUPE ADP" 2010 "FR0010340141" " 7/26/2010" "SANOFI" 2010 "FR0000120578" " 3/31/2010" "PEUGEOT" 2010 "FR0000121501" " 4/13/2010" "AVENIR TELECOM" 2010 "FR0013529815" " 2/4/2010" "TELEPERFORMANCE" 2010 "FR0000051807" " 7/1/2010" "GROUPE GORGE" 2010 "FR0000062671" " 6/25/2010" "ACTIA GROUP" 2010 "FR0000076655" "10/21/2010" "GROUPE LDC" 2010 "FR0013204336" " 4/22/2010" "ALSTOM SA" 2010 "FR0010220475" " 10/4/2010" "RISC GROUP" 2010 "FR0004038248" " 2/9/2010" "vinci" 2010 "FR0000125486" " 4/4/2010" "norbert dentressengle" 2010 "FR0000052870" "12/16/2010" "THALES" 2010 "FR0000121329" "11/25/2010" "Air France" 2010 "FR0000031122" " 7/5/2010" "SELECTRIC" 2010 "FR0000121972" " 3/31/2010" "renault" 2010 "FR0000131906" "11/23/2010" "SPIR COMM" 2010 "FR0000131732" " 3/1/2010" "psa" 2010 "FR0000121501" "11/18/2010" "sanofi" 2010 "FR0000120578" " 12/6/2010" "maison valerie" 2010 "" " 2/24/2010" end
Comment