topic Re: Order the variables in New SAS User

Order the variables

ha1331 — Fri, 25 Sep 2020 10:53:28 GMT

Hi everyone,

I have a data sample like this:

Firm Year IPO_year

A 2000 0

A 2001 1

A 2002 0

A 2003 0

B 2007 0

B 2008 1

B 2009 0

C 2013 0

C 2014 0

I want to count the number of years after IPO for each firm, so what I want to get is another column like this:

Firm Year IPO_year Year_After_IPO

A 2000 0 0

A 2001 1 1

A 2002 0 2

A 2003 0 3

B 2007 0 0

B 2008 1 1

B 2009 0 2

C 2013 0 0

C 2014 0 0

(All the years before IPO will be zero).

I have tried this code:

data X;

set Y;

by Firm;

if IPO_year = 1 then d+1;

run;

but this code is not reset for new firm. Could any one can help me with this?

Thank you very much in advance!

Re: Order the variables

PaigeMiller — Fri, 25 Sep 2020 11:08:55 GMT

You can use if first.firm to reset the calculations to zero, as shown below.

data want;
	set have;
	by firm;
	retain ipo_flag;
	if ipo_year=1 then ipo_flag=1;
	if first.firm then do;
		year_after_ipo=0;
		ipo_flag=0;
	end;
	if ipo_flag then year_after_ipo+1;
    drop ipo_flag;
run;

Re: Order the variables

ha1331 — Fri, 25 Sep 2020 11:34:40 GMT

Many thanks!!!!

That's just awesome. It works so well.

Thanks a lot!

Re: Order the variables

Tom — Fri, 25 Sep 2020 12:56:42 GMT

Your first two IF statements are out of order. It only works for the sample data because no firm has IPO in the first year.

Re: Order the variables

ha1331 — Fri, 25 Sep 2020 12:59:54 GMT

Right. Thanks for noticing me about that.

I checked the data and changed the order of the two if statements. It works well after that.