Pull First Set of Observations Based Off The First Date and an Identifier Variable

[Chutzler]

Hello,

This is my first time submitting a question! Exciting stuff!

So, I am trying to keep the first set of observations based off of two variables. Here is an example dataset:

Have:

datadate	gvkey	eventdate
3/31/2001	5	10/1/2004
6/30/2001	5	10/1/2004
9/30/2001	5	10/1/2004
12/31/2001	5	10/1/2004
3/31/2002	5	10/1/2004
6/30/2002	5	11/4/2005
9/30/2002	5	11/4/2005
12/31/2002	5	11/4/2005
3/31/2003	5	11/4/2005
6/30/2003	5	11/4/2005

 Want:

3/31/2001	5	10/1/2004
6/30/2001	5	10/1/2004
9/30/2001	5	10/1/2004
12/31/2001	5	10/1/2004
3/31/2002	5	10/1/2004

To be clear, what I would like to pull from this dataset is the first five rows. So, all observations that have the first event date for each gvkey. What I'm having trouble doing is pulling all five observations. I can pull just the first observation based off of event date and gvkey, but I haven't figured out a way to pull all five. Thanks!

[Reeza]

And you know it's 5 because of the value in GVKEY?

Is this done once or does it need to be done for each group?

data want;
set have;

by eventDate gvkey;
if first.eventDate then count=0;

count+1;

if count<= gvkey;

run;

---

@Chutzler wrote:

Hello,

This is my first time submitting a question! Exciting stuff!

So, I am trying to keep the first set of observations based off of two variables. Here is an example dataset:

Have:

datadate	gvkey	eventdate
3/31/2001	5	10/1/2004
6/30/2001	5	10/1/2004
9/30/2001	5	10/1/2004
12/31/2001	5	10/1/2004
3/31/2002	5	10/1/2004
6/30/2002	5	11/4/2005
9/30/2002	5	11/4/2005
12/31/2002	5	11/4/2005
3/31/2003	5	11/4/2005
6/30/2003	5	11/4/2005

 Want:

3/31/2001	5	10/1/2004
6/30/2001	5	10/1/2004
9/30/2001	5	10/1/2004
12/31/2001	5	10/1/2004
3/31/2002	5	10/1/2004

To be clear, what I would like to pull from this dataset is the first five rows. So, all observations that have the first event date for each gvkey. What I'm having trouble doing is pulling all five observations. I can pull just the first observation based off of event date and gvkey, but I haven't figured out a way to pull all five. Thanks!

---

[Chutzler]

Sorry, I should have clarified. It needs to be done for each group. I don't know it's 5 because of the value of the GVKEY. It could be more or less than five. The GVKEYS are typically six digit identifiers. Maybe this will be more clear:

Have:

datadate	gvkey	eventdate
3/31/2001	001577	10/1/2004
6/30/2001	001577	10/1/2004
9/30/2001	001577	10/1/2004
12/31/2001	001577	10/1/2004
3/31/2002	001577	10/1/2004
6/30/2002	001577	11/4/2005
9/30/2002	001577	11/4/2005
12/31/2002	001577	11/4/2005
3/31/2003	001577	11/4/2005
6/30/2003	001577	11/4/2005
3/31/2001	004324	9/3/2005
6/30/2001	004324	9/3/2005
9/30/2001	004324	9/3/2005
12/31/2001	004324	9/3/2005
3/31/2002	004324	9/3/2005
6/30/2002	004324	9/3/2005
9/30/2002	004324	10/12/2006
12/31/2002	004324	10/12/2006
3/31/2003	004324	10/12/2006
6/30/2003	004324	10/12/2006

Want:

datadate	gvkey	eventdate
3/31/2001	001577	10/1/2004
6/30/2001	001577	10/1/2004
9/30/2001	001577	10/1/2004
12/31/2001	001577	10/1/2004
3/31/2002	001577	10/1/2004
3/31/2001	004324	9/3/2005
6/30/2001	004324	9/3/2005
9/30/2001	004324	9/3/2005
12/31/2001	004324	9/3/2005
3/31/2002	004324	9/3/2005
6/30/2002	004324	9/3/2005

[Reeza]

So why is it 5 for GVKEY=001577 and 6 for GVKEY=004324?
How do you know that?

[novinosrin · Accepted solution]

@Reeza  My understanding is that the OP wants just the 1st event records for each GVkey regardless of how many records the 1st event may contain

data have;
input datadate	:mmddyy10. gvkey $	eventdate :mmddyy10.;
format datadate eventdate mmddyy10.;
cards;
3/31/2001	001577	10/1/2004
6/30/2001	001577	10/1/2004
9/30/2001	001577	10/1/2004
12/31/2001	001577	10/1/2004
3/31/2002	001577	10/1/2004
6/30/2002	001577	11/4/2005
9/30/2002	001577	11/4/2005
12/31/2002	001577	11/4/2005
3/31/2003	001577	11/4/2005
6/30/2003	001577	11/4/2005
3/31/2001	004324	9/3/2005
6/30/2001	004324	9/3/2005
9/30/2001	004324	9/3/2005
12/31/2001	004324	9/3/2005
3/31/2002	004324	9/3/2005
6/30/2002	004324	9/3/2005
9/30/2002	004324	10/12/2006
12/31/2002	004324	10/12/2006
3/31/2003	004324	10/12/2006
6/30/2003	004324	10/12/2006
;


data want;
  set have;
  by gvkey eventdate;
  if first.gvkey then n=1;
  else if first.eventdate then n+1;
  if n=1;
  drop n;
run;

datadate	gvkey	eventdate
03/31/2001	001577	10/01/2004
06/30/2001	001577	10/01/2004
09/30/2001	001577	10/01/2004
12/31/2001	001577	10/01/2004
03/31/2002	001577	10/01/2004
03/31/2001	004324	09/03/2005
06/30/2001	004324	09/03/2005
09/30/2001	004324	09/03/2005
12/31/2001	004324	09/03/2005
03/31/2002	004324	09/03/2005
06/30/2002	004324	09/03/2005

[Chutzler]

Awesome, this worked! Thanks so much!