A discrete, univariate distribution modelling the number of ${\rm Bernoulli}(p)$ trial successes until a specified number of failures occur.

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4 views

Converting logarithmically transformed negative binomial coefficients to effect size at mean

I have logarithmically transformed coeficients, from a negative binomial regression, and am looking to calculate from these the unit change in y from a one-unit change in x. It is my understanding ...
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2answers
469 views

Expected number of times to roll a die until each side has appeared 3 times

What is the expected number of times you must roll a die until each side has appeared 3 times? This question was asked in primary school in New Zealand and it was solved using simulations. What is ...
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12 views

Obtaining AICc weights after glm.nb

I am performing negative binomial regression using glm.nb() function from MASS package and calculating AICc using package "AICcmodavg". I need also to obtain the (AICc) weights using aictab() function ...
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1answer
41 views

negative binomial modelling for child pedestrian accidents

I am currently try to model child pedestrian casualties for each ward in England and to create a model that will predict how many casualties per area based on social and economic qualities of the area ...
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0answers
8 views

Negative significance between zeros in GEE-Binary logistic model

In my experiment I record individuals response (yes or no,coded as 1 or 0) to 4 different treatments, in each trial all treatment are tested and repeated 10 times each but in random order. Thus I have ...
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0answers
7 views

Comparing results from reference coding and orthogonal coding in a linear model?

The problem: I'm trying to fit a zero-inflated negative binomial model to count data (catches of larval fish). I have three factors, and an offset variable, which is the volume of water filtered by ...
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1answer
62 views

Help with zero-inflated generalized linear mixed models with random factor in R

My study has a complicated design and I am not sure if I am modeling my zero-inflated data correctly. I have seed abundances and seedling abundances for 11 species. I have one main "treatment" with ...
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0answers
13 views

Plotting Negative Binomial curves in GGplot

I am trying to plot this data with a negative binomial curve and I keep coming up with this warning label. Now, I know what the theta is, but I can not figure out where in the code to specify it. ...
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0answers
45 views

zero-inflated negative binomial in Stata

I am trying to run a zero-inflated negative binomial analysis in Stata (zinb). My question/problem is this: the model's convergence seems dependent on which and how ...
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0answers
2 views

What component of the result should I look at when doing a LLM model fit?

I am running mixed effects models with poisson and negative binomial fits. To asses which of the models are better, what components of the models should I look at? Some popular methods I follow: a) ...
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23 views

Two more questions about Count Data

I almost became an opponent of the transformation of count data. (quite famous reference). But I still did not find answers to some important questions about non-transformed count data (I consider ...
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2answers
50 views

Negative Binomial to Normal

I want to use normalisation technique that has assumption of residuals' normality (GLMs), but my data is $\sim$Negative Binomial. Can I map values from NB distributed distribution to Normal ...
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0answers
13 views

Negative Binomial Problem (parameter estimation)

I have quite a tricky problem. Assume we have vector of random variables: $v = \{\xi_1, \ldots, \xi_n\}$. Each random variable is $NB$ distributed. Asuume we have several vectors $v$, and we have ...
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46 views

Zero Inflated Versus Negative Binomial Models Conundrum

I have a count variable that represents the number of new band foundings in a country-year. However, there is zero inflation as there are no foundings for most country-year. There is also ...
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0answers
38 views

Dependent variable is count data, which method to use?

Which method should I use to analyse the relationship between count variable (absent days) and other 4 variables? Should I standardise Size variable? Please recommend some further literature/ ...
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0answers
20 views

How to compare two Negative Binomial samples with different parameters

I found similar questions on CrossValidated, but none of them answer this question directly. I have two ordered samples, from RVs: $\xi_1 \sim NB(size=r_1, prob=p_1)$ and $\xi_2 \sim NB(size=r_2, ...
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1answer
94 views

Fitting negative binomial distribution to large count data

I have a ~1 million data points. Here is the link to file data.txt Each of them can take a value between 0 to 145. It's a discrete dataset. Below is the histogram of dataset. On x-axis is the count ...
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0answers
9 views

Accounting for different sample totals in Negative Binomial GLM

I am working with overdispersed count data, looking at rate of infection in populations along a gradient. I have multiple transects per site, and although the length of each is constant, the number ...
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0answers
10 views

What is the best test to measure deviations from tiny proportions?

What is the best (most reliable and robust) test to measure deviations from tiny expected proportions (e.g., p0 < 10^-6) in a huge sample? Binomial? Poisson? Negative binomial? Something else? ...
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1answer
33 views

Why is the Negative Binomial typically preferred over the Poisson?

I know that the Poisson is a special type of negative binomial, but from some shallow readings I've noticed that people claim that the Negative Binomial is better than the Poisson as it accounts for ...
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9 views

How to test predictability of an explanatory model?

As a part of my research I create an explanatory negative binomial regression model. Now, I want to show this model can also have predictability power. I don't want to compare my model with other ...
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0answers
26 views

MLE for Negative Binomial self study [closed]

Question 3 p(x)=((x_i+r-1)¦x_i )θ^r〖(1-θ)〗^(x_i ) L(x)=∏n_(i=1)((x_i+r-1)¦x_i ) θ^r〖(1-θ)〗^(x_i ) l(x)=∑n_(i=1)〖[log((x_i+r-1)¦x_i ) 〗+rlog(θ)+x_i log⁡(1-θ)] (∂l(x))/∂θ=〖∑n_(i=1)(r/θ〗-xi/(1-θ)) ...
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24 views

MLE for Negative Binomial Distribution [closed]

Let x1,...,xn be iid sample from a Negative Binomial Distribution where r>0 is an integer number, θ∈(0,1) and is the binomial coefficient. Suppose that r is given, find the MLE of θ. hey guys I ...
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21 views

Robust Estimation of Negative Binomial: Help in understanding the code

I would like to understand following R code. Robust methods used here works, I understood it, but sometimes too many options for choice is not a good thing - now I am confused which method should I ...
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15 views

How to decide between quasi-poisson and negative binomial?

I tried quasi-poisson and negative binomial glms on my counted data in R. The estimates are pretty much the same but p-value are different. Quasi-poisson gives insignificant result. NB give ...
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33 views

Selecting Link Function for Negative Binomial GLM

I'm trying to model insect abundance data with a variety of vegetation/site related covariates. Because it is count data that is over-dispersed, I've decided to use the negative binomial distribution. ...
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49 views

Questions about negative binomial distribution

1) I know that my data is NB distributed. But also I know that it has several outliers (probably, zeros and extremely big numbers). How can I estimate NB? I found the trick answered here, on CV site, ...
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0answers
9 views

Modeling different rates with same offset

I'm working on my PhD and trying to analyze some data and would appreciate anybody's two cents. I'm going to trying to explain my issues with a simplified example below. Generally, I am trying to ...
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1answer
53 views

Negative Binomial dispersion parameter in SPSS

I am working in accident prediction modeling and I'm using SPSS Generalized Linear Model procedure with Negative Binomial distribution and Log Link Function. Does anyone know the form in wich SPSS ...
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0answers
9 views

Poisson regression with days per week as the DV

I am estimating a poisson model (and negative binomial for comparison) with the number of days in a week that a person made a fishing trip as the dependent variable. The range of this variable is ...
3
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1answer
75 views

Incorporating auto-correlation structure into a negative binomial generalized additive mixed model using mgcv in R

I'm working with fish migration time series data, and I am modeling fish counts using environmental variables. I am using a generalized additive mixed model from the mgcv package in R. I am using a ...
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0answers
30 views

Fit a Negative Binomial or use a power transformation for Machine Learning

I have data that is $\mathcal{NB}$-distributed. I have only ~100 data points in one sample. I have tried to fit Negative Binomial to the data, but at first I decided to do simulations: ...
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1answer
50 views

Regression model for country-year level data

I have a data set which includes country-years and I am interested in modeling founding and mortality for corporations in each country-year. I am interested in within- as well as between-country ...
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27 views

Combinations of Bernoulli Trials

I recently asked another question, which I have linked here: Combining Binomial Random Variables. I wanted to add onto that question, so I am asking in a different thread. Brief recap of previous ...
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1answer
36 views

Analysis of count data (density per area) using Generalized linear model

We are applying a GzLM (using SPSS) for analysing the effects of two fixed categorical predictors (habitat type (2 levels) and seasons (4 leves), and their interaction, on data regarding counts per m2 ...
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0answers
35 views

McFadden pseudo R squared on GLM.NB

I have used the McFadden pseudo R squared on a negative binomial glm (family=poisson). I was wondering if it's appropriate. I have found informations suggesting McFadden is useful for poisson glm but ...
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0answers
15 views

Iterative Maximization issue in Truncated Negative Binomial Regression in Stata

I was running truncated negative binomial regression in Stata and got a problem. During the iteration process, my results show " backed up" at the end of final iteration which means Stata could not ...
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0answers
15 views

Truncated Negative Binomial Regression (Stata): Missing/Blank Significance value

I was running truncated negative binomial regression (tnbreg) in STATA and got the answer but when I added [pweight = weighting variable ] to weight dependent variable to address endogenous ...
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0answers
10 views

Probability of Pr(N=0) as function of Panjers (a,b) parameters

Is there a way to find the general formula for Pr(N=0) as the function of Panjers parameters a and b for Binomial, Negative Binomial and Poisson distributions? It is possible to show e.g. parameters ...
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39 views

R hurdle and vuong tests giving strange results

So I'm trying to fit a hurdle model with the count distribution as negative binomial. I get the following outputs for assuming negative binomial and poisson: ...
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0answers
217 views

Switch from Modelling a Process using a Poisson Distribution to use a Negative Binomial Distribution?

We have a random process that may-or-may-not occur multiple times in a set period of time $T$. We have a data feed from a pre-existing model of this process, that provides the probability of a number ...
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1answer
164 views

Panel count data, choosing between xtpoisson cluster-robust versus negative binomial

I have a panel count data and I would like to estimate it with fixed effects. My data shows a little bit of overdispersion (when fitted with quasi-poisson the overdispersion parameter is 5.01 and the ...
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1answer
51 views

Calculating OR and IRR for a zero-inflated negative binomial model from estimates

I used the PSCL package to run a zero-inflated negative binomial model on some count data I have. This package gives the following output: for the zero part of the model: ...
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0answers
10 views

Separating zero mean from other means

I have counts as responses to a treatment with several levels including a positive and a negative control. The positive control has a mean value approximately 10 times the 2nd highest mean; while the ...
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0answers
12 views

Can I run a system of equations (3SLS) with one linear and one nonlinear regression?

I am investigating determinants of investments (in mio. $) in a sector and determinants of technology developments (patent count) in the same sector. The study is a panel study over 50 countries and ...
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1answer
17 views

Frequency Data, Model Choice (Poisson with Offset, Fractional Regression)

I have text data and am interested in estimating the effect of some covariate on word frequency. All the frequencies are very small. The unit of observation is a single document. I'm trying to think ...
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0answers
10 views

Computing a growth rate starting from a negative-binomial-regression coefficient

I need to estimate the growth rate of a factor in time. The available information consists of a coefficient from a negative binomial regression, where this factor is the dependent variable and time is ...
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0answers
16 views

Counts vs. percentage of predictor variables in the presence of an offset

The case: I am using negative binomial models to predict the number of deaths per household for four African countries. I am using an offset (log number of household members) to obtain estimates of ...
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0answers
18 views

Buy Till You Die(BTYD) - Individual LTV scores

I'm using the Buy Till You Die(BTYD) package in R to predict LTV (using Pareto/NBD), and I've been able to produced expected transactions by week, but is there a way to predict the dollar value of ...
11
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1answer
635 views

Diagnostics for generalized linear (mixed) models (specifically residuals)

I am currently struggling with finding the right model for difficult count data (dependent variable). I have tried various different models (mixed effects models are necessary for my kind of data) ...