In the Help we read, as regards the accessor $llt
<<
$llt
Output:     series
For selected models estimated via Maximum Likelihood, returns the series 
of per-observation log-likelihood values.
At present this is supported only for binary logit and probit, tobit and 
heckit.
> 
But what if I estimate a model using the mle  command in a hand-made a 
script? Will the accessor work?
It appears not:
After the "end mle" line I typed
series llobs = $llt
and I got "The statistic you requested is not available". But maybe I 
have not incorporated it correctly.
Motive: I need the per-observation log-likelihood values to run Vuong's 
(1989) LR tests to select between non-nested models.
-- 
Alecos Papadopoulos
PhD Candidate
Athens University of Economics and Business, Greece
Department of Economics
https://alecospapadopoulos.wordpress.com/