Q: How do I drop financial firms.

A: In accounting/ finance research, we often drop financial or regulated industries as they are quite different from industries in terms of operations and regulations.

So to drop finance firms, which have SIC 4 digit code from 6000 to 6999, we can use the following code.

drop if inrange(sic4,6000,6999)

**A lesson elegant way would be:

drop if sic4>=6000 | sic4<=6999