R Squared using did2s

[Cat Santos]

Dear Statalist Community,

I am using did2s for a difference-in-differences analysis. However, this command goes not report the R-squared. My model:

 did2s output if subsample==1 [aw=_weights],
 first_stage(i.country_id i.year control1 control2 control3 control4 control5)
 second_stage(treat) treatment(treat) cluster(country_id)

I was thinking of doing something like:

 *predict outputp if e(sample)
 *corr output outputp if e(sample)
 *di r(rho)^2

However, I was wondering if this would work in the context of did2s...

Could someone kindly let me know how I can calculate it?

Thank you!

Cat Santos