st: XTPMG - conformability error

["Vezzani, Antonio (ESA)" <Antonio.Vezzani@fao.org>]

Dear statalist users,

I'm trying to use the xtpmg command but I get this type of error.

. xtpmg d.gdp_capita d.pop, lr(gdp_capita pop)

Iteration 0:   log likelihood = -12905.298  
Iteration 1:   log likelihood = -12902.763  
Iteration 2:   log likelihood = -12902.392  
Iteration 3:   log likelihood = -12902.392  
conformability error
r(503);

Any insight on where I am wrong?
(the panel is balanced, I use stata11 and the examples proposed by the authors works)


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