Hi. I have panel data from 2009-2016. I want to remove individuals from the data set if the variable of interest is always negative (negative in each year). However, if the variable is positive in one or more years then I want the individual to still be in the data set for all years, including their negative value. I will try illustrate the problem:

ID Year VAR1
1 2009 -10
1 2010 10
1 2011 5
1 2012 -3
2 2009 -1
2 2010 -2
2 2011 -5
2 2012 - 9

Desired outcome:
ID year var1
1 2009 -10
1 2010 10
1 2011 5
1 2012 -3

In this case, individual 2 should be dropped, while individual 1 shall remain in the data set, with the values for each of the years, indepenent of negative values.

All help is greatly appreciated.