st: non-concave in negative binomial model

[wying1@umbc.edu]

Hi, all,


When I tried a series of models for count dependent variable estimation
(nbreg,zinb), there was an indication of "not concave" for the iteration 0
- 1 in "fitting constant-only model".  What does this mean?  How would
that affect my estimation?


Thanks a lot,
Ying

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