Thanks very much!
Nick's FAQ was very helpful. The egen ,nvals() command did the trick.
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Martin Weiss
Sent: Freitag, 2. Oktober 2009 17:22
To: [email protected]
Subject: st: AW: counting members of groups in unbalanced panel data
<>
Here is code for your first item requested:
*************
clear*
inp CompanyID FundID Strategy str10(Date Return)
3021 205 2 "Jan 94" X
3021 205 2 "Feb 94" X
3021 405 3 "Jan 94" X
4671 904 9 "Feb 94" X
4671 904 5 "Mar 94" X
4671 154 1 "Mar 94" X
end
compress
list, noobs
gen month=monthly(Date, "M19Y")
format month %tmMonth_CCYY
drop Date
//"total number of companies per month"
bys month CompanyID: gen numcomp=_n==1
la var numcomp "# of companies per month"
by month: replace numcomp = sum(numcomp)
by month: replace numcomp = numcomp[_N]
l, sepby(month) noob
*************
With regard to your code, you may want to note that -egen, count()- merely
counts the nonmissing expressions (not the distinct ones), and you may want
to check whether this councides with your intentions...
***
clear*
input x
1
1
1
.
1
2
3
end
compress
egen myvar=count(x)
list, noobs
***
HTH
Martin
-----Ursprüngliche Nachricht-----
Von: [email protected]
[mailto:[email protected]] Im Auftrag von Oliver
Weidenmueller
Gesendet: Freitag, 2. Oktober 2009 16:49
An: [email protected]
Betreff: st: counting members of groups in unbalanced panel data
Hello everyone
I am having troubles figuring out how to in a panel data structure to derive
some descriptives.
In my data
- there are mutliple companies, each having 1 to many funds
- each fund being of one of 11 strategies
- each fund only showing observations for part of the total sample period.
I require
- the total number of companies per month
- the average (median, max) number of funds per company per month
- the average (median, min, max) number of strategies per company per month
The data format is for example like this:
CompanyID FundID Strategy Date Return
3021 205 2 Jan 94 X
3021 205 2 Feb 94 X
3021 405 3 Jan 94 X
4671 904 9 Feb 94 X
4671 904 5 Mar 94 X
4671 154 1 Mar 94 X
...
Number of funds per family per month was easy:
by companyid mydate ,sort: egen perfamnrofunds = count(R)
But now I ran into troubles. I would greatly appreciate if anyone could
help.
Thanks in advance,
Best regards,
Oliver
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
