Dear all,

For my master's thesis, I'm trying to look at the effect of a policy change on women's labour force participation, using a diff-in-diff analysis with individual fixed effects. For my main analysis, I use two waves of data (2009 and 2014, with the change happening in 2011). Having found no effect on female participation overall, I would now like to look at differences by subgroups, in particular by marital status.

My question is whether using the if condition after the xtreg command is appropriate in this setting; since I am looking at a sample of rather young individuals, many women get married between 2009 and 2014. If I understand correctly, using "if married==1" would include women in the 2014 analysis who were not married yet in 2009, unbalancing the panel. Whilst I know that xtreg can deal with unbalanced panels, I wonder whether it makes sense to include women who are married in 2014, but not in 2009, given that marriage and labour force participation are likely to be correlated. Should I just focused on the subsample of women who are married in both 2009 and 2014?

Many thanks in advance and apologies if this is not a 'proper' Stata question but rather a more scientific question!

Kind regards,

Anna