st: Create a flag (panel data)

[R Zhang <r05zhang@gmail.com>]

Dear Statalisters,

I have the following panel data (only provided a small number of observations)

PatentID: is the identification number for company AA’s patent,
citedID is the identification number of a patent that was cited by the
focal patent. I want to generate a dummy that flags the citedID under
the following condition:

citedID=1 if this patent (e.g. 1995 100002 was firm AA’s own patent
filed over the past 5 years, Or 100002 was a patent that was cited by
firm AA over the past 5 years).  Could you suggest a good way of doing
this?  Thanks !!!

Year       firmid    patentID              citedID

1995      AA           100001            100002

1995      AA           100001            100003

1995      AA           100001            100004

1994      AA           110001            100002

1994     AA           110001            100005

1994     AA           110001            120001

1993      AA           120001            100006

1993      AA           120001            100007

1992      AA           130001            100008

1992      AA           130001            100009

1991      AA           140001            1000010

1991      AA           140001            100011

-Rochelle

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