29k views

### Where does the offset go in Poisson/negative binomial regression? [duplicate]

(First of all, just to confirm, an offset variable functions basically the same way in Poisson and negative binomial regression, right?) Reading about the use of an offset variable, it seems to me ...
130 views

### Poisson regression - is offset term required? [duplicate]

I am modeling rates of people given drug $X$ or drug $Y$, working out probability of getting drug. The drug $X$ and drug $Y$ points have been matched on exposure time (person years) to specific drug. ...
97 views

### How to take population size into account when running a Poisson regression? [duplicate]

My data takes the following form: Outcome variable = no of suicides (count data) Explanatory variables = Age (grouped into young, middle and old), Gender, Country, Year I am running a Poisson ...
33 views

### POISSON REGRESSION AND OFFSET VARIABLE [duplicate]

I am using a Poisson regression model with a count data. More specifically, my dependent variable is the number of children dead. My feeling is that I could use a Poisson model with an offset ...
320k views

### In linear regression, when is it appropriate to use the log of an independent variable instead of the actual values?

Am I looking for a better behaved distribution for the independent variable in question, or to reduce the effect of outliers, or something else?
27k views

### How to decide which glm family to use?

I have fish density data that I am trying to compare between several different collection techniques, the data has lots of zeros, and the histogram looks vaugley appropriate for a poisson distribution ...
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### 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 ...
10k views

### Identical coefficients estimated in Poisson vs Quasi-Poisson model

In modeling claim count data in an insurance environment, I began with Poisson but then noticed overdispersion. A Quasi-Poisson better modeled the greater mean-variance relationship than the basic ...
5k views

### Should I use an offset for my Poisson GLM?

I am carrying out research to look at differences in fish density and fish species richness when using two different underwater visual census methods. My data was originally count data but then ...
12k views

### What are the differences between survival analysis and Poisson regression?

I'm working on a classical churn prediction problem using the number of visits of a given user to a site and I thought that Poisson Regression was the right tool for modelling the future engagement of ...
17k views

### How to deal with “non-integer” warning from negative binomial GLM?

I am trying to model the mean intensities of parasites affecting a host in R using a negative binomial model. I keep getting 50 or more warnings that say: ...
9k views

### Whether to use an offset in a Poisson regression when predicting total career goals scored by hockey players

I've got a question concerning wheter or not to use an offset. Assume a very easy model, where you want to describe the (overall)number of goals in hockey. So you have goals, number of games played ...
4k views

### Regression model where output is a probability

I am trying to fit a model, and have the suspicion that what I am doing is not quite right. The data tracks what proportion of people made a decision, and what factors were active when they made their ...