st: unbalanced panel with xtabond

[Caterina Astarita <lasta01@students.bbk.ac.uk>]

Dear Statalisters, 

I'm studying the do file of an article that consider an unbalanced panel dataset. 
I'm not very familiar with unbalanced panel dataset and at the moment I use xtabond2 whereas 
the do file I'm considering uses xtabond. 

The questions are 

_ in xtabond is there any specific command to account for the fact the panel is unbalanced?

_ the command "xi: xtabond homiciderate householdsize popdensity urban femlabourpart i.period,
               pre(lngdp econgrowth male1564 freedom freedomsq deathp humanrightsviol econdisc) robust"

that I found in the do file I'm studying does consider the fact the panel is unbalanced or it does work as 
it was balanced? 

Thank you 

Caterina
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