- data a;
- input date firm sto;
- cards;
- 1 1 1.1
- 2 1 1.3
- 3 1 2.1
- 4 1 1.1
- 5 1 2.3
- 1 2 1.1
- 2 2 2.1
- 3 2 1.5
- ;
- run;
-
- data b;
- retain t;
- set a;
- by firm;
- if first.firm then t=0;
- if t = 0 then output;
- if sto>2 then t=1;
- drop t;
- run;


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