Questions tagged [conway-maxwell-poisson-distribution]
The Conway-Maxwell-Poisson distribution is a discrete distribution with support over the natural numbers. It has two parameters and can be either over- or underdispersed. It is a member of the exponential family, has the Poisson and geometric distribution as special cases and the Bernoulli distribution as a limiting case.
8 questions
1 vote
1 answer
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glmmTMB model gives AIC value and coefficient estimates, but no z or p values
I am modeling count data with a non-Poisson distribution and potential zero inflation in glmmTMB. I am using different distributions and zero inflation specifications, including Conway Maxwell Poisson,...
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1 vote
0 answers
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Does pseudo-R2 represent an appropriate measure of goodness-of-fit for Conway-Maxwell Possion?
I have fit a model using glmmTMB as such: ...
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0 votes
0 answers
47 views
Appropiate distrution to model under-dispersed count data with missing zero class
I am working in the problem of finding the missing zero-class of data that comes from a counting event. My data is highly under-dispersed. In some cases: $$ \bar{x}/s^2 >20, $$ with $\bar{x}$ and $...
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4 votes
1 answer
714 views
How to simulate from the Conway–Maxwell–Poisson distribution?
I want to run a simulation study and I need to simulate data from the Conway–Maxwell–Poisson distribution. However, it seems like the probability mass function is not available in closed-form, so, I ...
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3 votes
1 answer
457 views
Conway-Maxwell-Poisson (CMP) - Coefficient interpretation (Log/IRR)
I'm using the Conway-Maxwell-Poisson (CMP) distribution to model the amount of nouns in a clause (data is under-dispersed). I've run the model using glmmTMB (family= "compois") but I'm ...
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0 votes
0 answers
397 views
Checking Conway-Maxwell-Poisson model adequacy
I am trying to troubleshoot model adequacy problems for underdispersed count data (number of correct responses in a simple task; dispersion ratio is 0.3) that I modeled with Conway-Maxwell-Poisson. ...
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1 vote
0 answers
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fitting COM-Poisson in R
I have some crash data I did Poisson for that and the data was underdispersed. I want to do COM-Poisson regression for my data. I see that every website suggest several packages for COM-Poisson and I'...
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3 votes
1 answer
1k views
Is there a common underdispersed discrete distribution with unbounded support for general mean and variance?
I have a mean $\mu$ and a variance $\sigma^2$ with underdispersion, i.e., $\sigma^2<\mu$. Is there a standard discrete distribution with these moments and unbounded-on-the-right support, i.e., ...
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