Hi everyone,

I have a dataset that that looks like this:

state year legis_control
NH 2009 Dem
NH 2010 Dem
NH 2011 Rep
NH 2012 Rep
NH 2013 Split
NH 2014 Split
NH 2015 Rep
NH 2016 Rep
NH 2017 Rep
NH 2018 Rep
NJ 2009 Dem
NJ 2010 Dem
NJ 2011 Dem
NJ 2012 Dem
NJ 2013 Dem
NJ 2014 Dem
NJ 2015 Dem
NJ 2016 Dem
NJ 2017 Dem
NJ 2018 Dem
NM 2009 Dem
NM 2010 Dem
NM 2011 Dem
NM 2012 Dem
NM 2013 Dem
NM 2014 Dem
NM 2015 Split
NM 2016 Split
NM 2017 Dem
NM 2018 Dem
I want to create a dummy whenever "legis_control" is constant within state. I have tried the following code as suggested in FAQ (https://www.stata.com/support/faqs/d...tions-in-group) and another posts:

by state (legis_control), sort: gen swing_state = legis_control[1] != legis_control[_N]

This seems to work both for states that are always constant ("NJ") and for those in which legis_control in 2009 differs from that of 2018 ("NH"). However, in states like "NM", the first and last observation are the same, but differ in the middle. Is there any way to fix this?

Thanks,

Zoel