Linked Questions

0
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0answers
48 views

Poisson regression with continuous data [duplicate]

I have a time series of floating numbers, say, 0.1, 0.5, 1.1, 0.6, 2.0, 1.4, 0.4 Now, I would like to model this series with Poisson regression, since the numbers, even though they seem ...
53
votes
9answers
3k views

What are some examples of anachronistic practices in statistics?

I am referring to practices that still maintain their presence, even though the problems (usually computational) they were designed to cope with have been mostly solved. For example, Yates' ...
17
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5answers
6k views

Poisson regression with large data: is it wrong to change the unit of measurement?

Due to the factorial in a poisson distribution, it becomes unpractical to estimate poisson models (for example, using maximum likelihood) when the observations are large. So, for example, if I am ...
17
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2answers
6k views

In a Poisson model, what is the difference between using time as a covariate or an offset?

I recently discovered how to model exposures over time using the log of (e.g.) time as an offset in a Poisson regression. I understood that the offset corresponds to having time as covariate with ...
16
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2answers
8k views

How is it possible that Poisson GLM accepts non-integer numbers?

I am really stunned by the fact that the Poisson GLM accepts non-integer numbers! Look: Data (contents of data.txt): ...
11
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2answers
10k views

Using poisson regression for continuous data?

Can the poisson distribution be used to analyze continuous data as well as discrete data? I have a few data sets where response variables are continuous, but resemble a poisson distribution rather ...
6
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2answers
7k views

Should I use Poisson distribution for non-integer, count-like data?

It's my first question here, I hope I'll ask it correctly. I am trying to find out how to analyse non-integer, count data (yes!). I am looking at the effect of a given treatment on habitat suitability ...
3
votes
1answer
773 views

How to regress a positive response variable that is also not a count variable?

I am asked to perform a regression on a dependent variable that only takes positive values. Intuitively one can think of Poisson or negative binomial, but unfortunately the response variable that I am ...
6
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0answers
4k views

Poisson regression for binary data

I've been trying to read up on Poisson regression models, and it looks like it is possible to estimate such a model with a binary outcome. This has come up before on this site here (and somewhat here ...
3
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1answer
2k views

What log-likelihood function do you use when doing a Poisson regression with continuous response?

I am given $N$ observations of pairs of covariates and response $(\mathbf{x}_i, y_i)$. When the response are non-negative integers, by doing Poisson regression I am modelling $y_i \sim \mathrm{Pois}(\...
4
votes
1answer
2k views

Percentages as the response variable in GLMM (glmer), proportional binomial or not?

After looking through several questions on stackexchange, and even applying many of the suggested methods I have come to a point where I would like to have an expert's advice if the methods applied on ...
4
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2answers
1k views

Why one can fit Poisson GLM on non-integer values in Stata?

I have aggregated death counts and some categorical predictors e.g. era, drug use, and I'm running a Poisson GZLM in SPSS, also a glm in Stata (generalized linear ...
2
votes
2answers
460 views

Why does Poisson GLM fit better to non-integer data?

Let's assume that I have a set of predictors and a non-negative integer resulting variable (number of events). All observations are repeated few times (it means that all predictors have the same ...
2
votes
1answer
749 views

Using Poisson instead of transforming the data

I note with interest an article which has been suggested to me over here: http://blog.stata.com/tag/poisson-regression/ I have the problems outlined in this blog - namely zeros (in the independent ...
1
vote
0answers
479 views

Panel poisson regressions on rates and values far from 0

I am estimating the effect of some treatment on yearly district-level stillbirths and stillbirth rates and births and birthrates in a panel with district and year fixed effects. Stillbirths are ...