Keep only first/last observation for EACH year of EACH company

[shafayat]

Can anyone please give me some clue how I can keep the last observation of "EACH" year of a specific company in a weekly panel data in order to annualize it? 

If I create year variable from the date and use last.year command, it only retains the last observation for the company, NOT the last for "EACH" year.

I tried sorting the data by year and then permno instead of by permno and then year, but had no luck; it then keeps only 1 observation from each year and deletes other years' data for other companies. 

Thanks.

[PGStats · Accepted solution]

1) Create a year variable

2) Sort by permno and year

3) then, in a data step do

data newData;

set myData; by permno year;

if first.year or last.year;

run;

[Astounding]

You will have to show your work.  It is entirely possible that you are using the correct tools, but using them incorrectly.  So post the program that isn't working.

[shafayat]

This is what I was doing. I was puzzled why it did not work. I don’t even know what changed but after quite a while it started working. Thanks though.