st: creating lag variables

[Reka Sundaram-Stukel <rsundara@wisc.edu>]

Dear Statalist,

I am trying to create a lag y for data that looks like the following:

id	type		choice 	Year	 lag_choice
1	a		1		1		-
1	b		0		1		-
1	c		0		1		-
1	d		0		1		-
1	a		0		2		1
1	b		0		2		0
1	c		1		2		0
1	d		0		2		0

how do I generate lag_choice. I have tried

by id type: gen lag_choice=choice[_n-1] and various combinations of 
this quite unsuccessfully. Help please

Thanks in advance

Reka


Reka Sundaram-Stukel
Graduate student
320 Taylor Hall
Department of Agriculture And Applied Economics
Madison, WI-53706


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