Hi all:
I am using an unbalanced panel dataset. i is ID and t is time. Every (i,t) has a characteristic x=0 or 1.
I want to generate a variable called "become" such that for each (i,t):
become=1, if x=0 at time t-1, and x=1 at time t
become=0, otherwise
How to write it? My primary concern is how to deal with the first t for each i--this observation does not have t-1.
Any suggestion would be greatly appreciated.
Ben
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