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Dear runmlwin users,

I am trying to analyse count data using a negative binomial distribution with a log link function. I have chosen a negative binomial distribution because the data exhibit overdispersion. As recommended for discrete response models, I am estimating the model with MCMC. When I run this specification for a relatively simple null model with two levels, I receive the message 'assertion is false'. However, the model runs fine when I estimate it using IGLS or if I change the distribution to Poisson. Could this message mean that a negative binomial distribution is not appropriate for the data?

As always, any help would be greatly appreciated!

Many thanks,

Jacqueline

The negative binomial distribution is currently not implemented in MLwiN when using MCMC estimation. We will try to provide a better error message to indicate this in a later release of runmlwin.

Hi Chris,

Thank you very much for your response.

Kind regards,

Jacqueline