GVKEY FY ID Join Start 1004 2000 1111 . 2000 1004 2001 1111 . 2000 1004 2002 1112 . 2002 1005 2000 1112 . 2000 1005 2001 1112 . 2000 1005 2002 1113 . 2002 1006 1995 1113 . 1995 1006 1996 1113 . 1995 1006 1997 1113 . 1995 1007 2005 1114 2002 2002 1007 2006 1114 2002 2002 1007 2007 1114 2002 2002 My desired result is the last column (start). What I am trying to do is the following: 1. If join (4th column) is given then start=join 2. If "join" is not given then start=fy. However, "start" will be only first FY based on ID. For example,  in the first row for ID 1111, the "start" is 2000 as it is the first year.  In the 2nd row for same ID 1111, the "start" is also 2000 not 2001.  in the 3rd row ID is changed. So, start=fy in the fourth row ID is same but gvkey is changed. So, for being a new gvkey(another company), for ID 1112, the start=fy and so on.    I don't know how to code this. Can anyone help me, please?  ... View more

Hi, I have many accounting variables that are illogically negative. I want to delete all the negative values from all the variables except a few whose values can be negative. I can do that in the following ways: if a<0 then delete; if b<0 then delete; so on. But this is not an efficient way to delete. Can anyone suggest me any efficient method?     ... View more

gvkey fyear at want 1001 2001 12.3 . 1001 2002 13.6 12.3 1001 2003 12.6 13.6 1001 2004 11.9 12.6 1002 2001 13.4 . 1002 2002 17.7 13.4 1002 2003 18.4 17.7 1002 2004 15.1 18.4   data want; set have; by gvkey fyear; if first.gvkey then want=.; else want=lag(at); run;   My data is already sorted. I am not getting the expected result. What is the mistake here?  ... View more