I would like to create leads and lags to control for the last two years before a pollical leader came to power and the first two years after they were out of power. Since I am using a Two Part Model I would like to create these as variables instead of using L2. or F2. I am using Stata 15.1.

I would like to do this within a loop so that a '1' is placed in the 2 years before n_power1. However, this isn't applicable to all leaders, because some leaders were in power before the analysis timeframe of 2000-2011. The dataset below is a subset of data that includes 2 political leaders.

I have tried several iterations that have not worked, most recently:
Code:
gen lag_birth=1 if n2_power1<n2_power1[_n-2]
Any suggestions are appreciated.

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input int n_year float(n_birth leader_id n2_power1 n2_power2)
2000 1 1 1981 2011
2001 1 1 1981 2011
2002 1 1 1981 2011
2003 1 1 1981 2011
2004 1 1 1981 2011
2005 1 1 1981 2011
2006 1 1 1981 2011
2007 1 1 1981 2011
2008 1 1 1981 2011
2009 1 1 1981 2011
2010 1 1 1981 2011
2011 1 1 1981 2011
2000 0 9 2009 2011
2001 0 9 2009 2011
2002 0 9 2009 2011
2003 0 9 2009 2011
2004 0 9 2009 2011
2005 0 9 2009 2011
2006 0 9 2009 2011
2007 0 9 2009 2011
2008 0 9 2009 2011
2009 1 9 2009 2011
end