assign value for a group under condition

[Zhongda]

Hi All,

I am new to sas and I was trying to achieve such thing:

here is the dataset:

PERMNO EVTDATE first_event inter_event

10001 8/1/11 1 0

10001 4/2/12 0 1

10002 7/6/98 1 0

10002 10/27/98 0 1

10011 11/13/95 1 0

10011 5/28/96 0 1

10011 5/29/96 0 1

10016 12/9/99 1 0

10016 5/3/00 0 1

10020 4/6/87 1 0

10020 10/21/87 0 1

10020 12/11/87 0 1

10020 4/17/90 1 0

10020 4/24/90 0 1

10028 8/17/99 1 0

10028 3/3/00 0 1

10028 7/14/06 1 0

10028 5/10/07 0 1

I would like to create another column call program and the column will state as:

PERMNO EVTDATE first_event inter_event define a program, and numbers of event in the group

10001 8/1/11 1 0 2

10001 4/2/12 0 1 2

10002 7/6/98 1 0 2

10002 10/27/98 0 1 2

10011 11/13/95 1 0 3

10011 5/28/96 0 1 3

10011 5/29/96 0 1 3

10016 12/9/99 1 0 2

10016 5/3/00 0 1 2

10020 4/6/87 1 0 3

10020 10/21/87 0 1 3

10020 12/11/87 0 1 3

10020 4/17/90 1 0 2

10020 4/24/90 0 1 2

10028 8/17/99 1 0 2

10028 3/3/00 0 1 2

10028 7/14/06 1 0 2

10028 5/10/07 0 1 2

let say for permno 10001, there are two obs and they form a program and the program has two event in a row, so it will be definded as 2 for each of the two obs.

Thank you so much for your help!

Appreciated,

Zhongda