fill in missing years b/w start year and end year

[Kyle Smith]

I am trying to fill in intermediate years when I have start and end years.

For example, consider the following dataset that includes firmid and the starting and ending years that the firm experienced a problem:

clear*
input firmid startyear endyear
11 2000 2002
11 2002 2003
12 2001 2003
12 2004 2004
13 2004 2005
13 2005 2005
end

I would like the output to be a firm-year panel with a column that indicated if that particular firm-year had a problem or not (where problem start and end dates came from the above data sample). The difficulty I have is when there is more than 1 year between the start and end date. I am not sure how to fill those years in. The output would look like this (there is a firm-year panel for 6 years for each of the 3 unique firms and a problem variable in the output set is equal to 1 if there was a problem in that particular year and zero otherwise):

clear*
input firmid year problem
11 2000 1
11 2001 1
11 2002 1
11 2003 1
11 2004 0
11 2005 0
12 2000 0
12 2001 1
12 2002 1
12 2003 1
12 2004 1
12 2005 0
13 2000 0
13 2001 0
13 2002 0
13 2003 0
13 2004 1
13 2005 1
end

Thank you in advance.

[Clyde Schechter]

preserve

keep firmid
duplicates drop
expand 6
by firmid, sort: gen year = 1999 + _n
tempfile rectangular
save `rectangular'

restore
joinby firmid using `rectangular'
gen byte problem = inrange(year, startyear, endyear)
collapse (max) problem, by(firmid year)

[Kyle Smith]

Clyde Schechter : that is the second time you've helped me in the last cpl days. Thanks alot. Wonderful and efficient coding. Have a great weekend.