Hello everyone,
I have a panel of 97 countries over 18 years and I would like to estimate a model with country and year fixed effects.

I have estimated the model with a difference GMM in the following manner.
Code:
xtabond2 y l.y l.x l.$controls i.Year, gmm(y x $controls_endog, lag(2 5) collapse) iv(i.Year l.$controls_exogen) noleveleq small noconstant robust
And, as far as I have understood, this model addresses the issue of fixed effects.

I have also estimated the model with at SYS GMM in the following manner:

Code:
xtabond2 y l.y l.x l.$controls i.Year, gmm(y x $controls_endog, lag(2 5) collapse) iv(i.Year l.$controls_exogen) small noconstant robust
And the results appear to be very different. Among other reasons to adjudicate between these models, my main concern is whether the System GMM accounts for the country fixed effects. As reading Roodman 2009 I did not fully understand whether this is the case.

I thank you in advance for your help

Best regards.