[Limdep Nlogit List] Question on missing values in N-logit

[Christoph Buschmann]

Dear group, 

I have a question on how N-logit deals with missing data in the covariates. My choice experi-ments were carried out completely by all respondents, but 8 respondents did not answer all questions about the covariates. 

I have ten choice cards per respondent and 3 alternatives in each choice situation. So, my dataset comprises three rows for each choice situation. N-Logit reports that, for the 8 respondents in question, per choice situation one missing value has been found and refers to the first row per choice situation, i.e. the row that gives information about the choice of alternative 1. 

I assume that, for the 8 respondents in question, N-logit skips one row per choice situation (the one for alternative 1), including the information about covariates, and keeps the other two rows (for alternatives 2 and 3).

This would mean that for the 8 respondents in question, some of the information is retained and so it makes sense to keep them in the data set. In fact, if I remove the 8 respondents from the dataset by hand, the model deteriorates (AIC).

What is your experience with missing data? Is my interpretation correct?

Thank you very much for your help.


Kind regards,
 
Christoph Buschmann

-- 
Christoph Buschmann, M.Sc. 

Stabsstelle Klima/ Coordination Unit Climate 
Thünen-Institut 
Bundesallee 49 
D-38116 Braunschweig 
Germany 

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