Questions tagged [beta-regression]

Beta regression is useful when the dependent variable is bounded, or when it has a ceiling or floor effect. It can also be used for modeling both the mean and the variance.

Filter by
Sorted by
Tagged with
2 votes
1 answer
39 views

Logit GLM and logit beta regression: Practical difference in the interpretation of the coefficients?

Terminology: By logit GLM I mean a generalized linear model with a binomial distribution and a logit link function. By beta regression I mean beta regression with a logit link function. I understand – ...
user avatar
  • 476
5 votes
3 answers
368 views

Proportion data with number of trials known (and separation?): GLM or beta regression?

I perform a lot of bioassays in which I score mortality not on individuals, but on groups of individuals as a proportion (the denominator, i.e., number of trials, is known): Sample Data: ...
user avatar
4 votes
1 answer
197 views

Beta regression shows a weird plot

I am trying to model the relationship between my response 'crop coverage [%]' ~ weed coverage [%] + Soil Moisture [%] using R. Since I am dealing with proportions, I chose to do a beta regression. ...
user avatar
  • 83
0 votes
0 answers
81 views

Differing confidence intervals between ggpredict() and ggemmeans() when REML = TRUE in glmmTMB beta regression

I am using the package ggeffects to estimate marginal effects and confidence intervals for a beta regression model fit with glmmTMB. I notice the estimates differ ...
user avatar
  • 77
0 votes
1 answer
49 views

Beta regression using categorical variables

I have been asked to do beta-regression for my data. The independent variable is categorical (there are three treatments A, B and C). The dependent variable is the proportion of time an animal is ...
user avatar
0 votes
0 answers
27 views

Can beta regression be used with continuous numerical data?

I am trying to fit a generalized linear model with Gamma distribution in R, but when I examine the residuals they are not normally distributed. I have a continuous numerical response variable, ...
user avatar
0 votes
0 answers
50 views

How do I write out the components of my beta regression, and how do I interpret them afterwards?

I am estimating a beta-regression using the logit-link function with a continuous dependent variable bound between 0 and 1 and 5 continuous predictor variables. In R the equation is given by: betareg(...
user avatar
0 votes
0 answers
73 views

Why are predictions from beta regression and linear regression identical?

I'm utilizing a beta regression to predict the relationship between x and y, since y is a proportion variable confined within the interval [0,1] but has no values of either 0 or 1. Outcomes on y only ...
user avatar
4 votes
3 answers
533 views

Why does my beta regression look linear when plotted?

Im using a beta regression to model since my dependent variable is confined between [0,1]. However, when I plot the relationship between x and y via my beta regression, the effect looks linear. When ...
user avatar
0 votes
0 answers
15 views

Beta-regression allowing for correlation of the error terms

I have a problem with beta-regression. In R exist a package "systemfit" that allows fitting regression (normal with identity link function) allowing for correlation of error terms. Anyone ...
user avatar
0 votes
1 answer
18 views

Fitting a beta mixed model

I would like some clarification on fitting a beta mixed model. My dependent variable is the proportion of days that patients take medication. For every patient(Patient.ID), the pharmacy either had an ...
user avatar
0 votes
0 answers
95 views

Selecting a betareg model out of all possible combinations of the EVs

I'm working on a dataset with response variable in [0,1] and n=61 observations, and trying to fit a model with betareg(). After posting my former question, I ...
user avatar
0 votes
2 answers
114 views

Appropriate Regression Model for Proportions and Rate Data

I have a problem where my dependent variable is given as a click-through rate and thus bounded [0,1]. While I have the traffic for each sample (a combination of design factors) and could reconstruct a ...
user avatar
2 votes
1 answer
84 views

Calculating different pseudo-$R^2$ for a betareg model

Sorry if this is a bit long.. I've been trying to fit models predicting the % of area infested in a field (response between 0 and 100%, total of 61 fields), with four explanatory variables, two ...
user avatar
1 vote
1 answer
127 views

How can I calculate a beta regression prediction from the coefficients?

I have applied the R betareg function to my data using the default logit link and phi precision log-link for the categorical data. My equation is: ...
user avatar
1 vote
0 answers
51 views

GAMM with BETAR(Link = "Logit") [closed]

I'm trying to use betar in gamm4 models but keep hitting an error. As far as I can tell, betar is one of the families that should be available - can anyone identify why I would keep hitting this error?...
user avatar
  • 11
1 vote
1 answer
30 views

Beta regression for ratio of counts

I have a question about whether it is appropriate to use beta regression when the proportion is formed as a ratio of counts. I have seen information suggesting it is fine and others pointing out that ...
user avatar
  • 47
2 votes
1 answer
77 views

Predict gamlss one-inflated beta model

How do you obtain predicted probabilities for the one-inflated component (nu model) of a one-inflated beta regression in gamlss? I have built the following model <...
user avatar
0 votes
0 answers
171 views

Interpretation of zero-inflated beta regression

I have constructed a zero-inflated beta regression model in gamlss. I find the output of this model somewhat confusing to interpret and was hoping that someone may ...
user avatar
0 votes
0 answers
54 views

Proper regression for my dataset - Zero-inflated beta regression?

I'm a bit stumped on the regression that I should be using for my dataset. There seems to be a general trend that as distance to a location decreases, the percentage of red material increases (as a ...
user avatar
0 votes
0 answers
40 views

Bayesian Beta regression with random effects in R

Does anyone know of an R package that does (Bayesian) Beta regression with random effects? We know of Bayesianbetareg but this doesn't include random effects so I'm ...
user avatar
  • 749
0 votes
0 answers
39 views

Setting priors for a beta distribution in R-INLA

I'm running a regression in R-INLA, where the response variable is proportion of grid squares suffering deforestation (by year, over a 20-year period). Setting the response for the last 5 years to NA ...
user avatar
1 vote
1 answer
55 views

meanBEINF vs predict(model, type = "response') in BEINF GAMLSS. and determining odds of predictor variable coefficient

A variation of this question has been asked, but certain items remain unanswered - I am modeling the proportion of mortality (Prop) using a single continuous predictor variable which is temperature (...
user avatar
3 votes
1 answer
610 views

Beta regression: how to interpret the p-value of the phi coefficient

I am applying a beta regression to my proportion data (breeding success). My Phi coefficients show a p value of 0.043, which seems considerably higher to most examples I have looked at. I fail to find ...
user avatar
0 votes
1 answer
277 views

Zero Inflated Beta Regression

How can we check that the proportions are inflated at zero and one while using Beta Regression?
user avatar
1 vote
0 answers
63 views

How to correctly specify and diagnose one-inflated beta regression mixed-models (using GAMLSS)

I would like to find out what variables influence/explain an efficiency score for an invasive species control method. As the score is defined on (0,1] and as some observations were not independent, I ...
user avatar
  • 383
0 votes
0 answers
21 views

Choice of statistical testing - under five mortality rate

I am not sure if this question or similar one has been asked before but I have checked and to the best of my knowledge couldn't find a suitable answer. Here is my confusion: I have a dataset with ...
user avatar
0 votes
1 answer
91 views

Structural Equation Modeling (SEM) with betareg in R

We have an SEM model and we were using Lavaan but we learned that the distribution of the residuals of one of the regressions is far from normal. The response variable in that equation is students' ...
user avatar
0 votes
1 answer
223 views

Interpreting interactions in beta regression

Edit I am using a log link and log(statemb) because my specific goal is to be able to conclude for small changes, an 1% increase in ...
user avatar
  • 3
1 vote
0 answers
50 views

Time series proportion/share modelling issue

I want to model import share (one commodity product in country) as dependent variable from local price premium (local price minus import price) and seasonality factor (0 or 1). Model is used to make ...
user avatar
  • 11
7 votes
1 answer
360 views

Which link function could be used for a glm where the response is per cent (0 - 100%)?

I am thinking about building a model (glm) where the response variable (y) is the cover (in per cent) of a plant species in a defined area, dependant of environmental variables. However, I don't think ...
user avatar
  • 175
0 votes
0 answers
39 views

Estimating proportion from aggregate data using regression

I am trying to estimate if a certain product is purchased by certain race(s) more than other. To do so, we have the following aggregate data Zip_code Percentage_of_buyers Asian_% Black_% Hispanic_% ...
user avatar
  • 1
1 vote
0 answers
46 views

Relationship between quasi-likelihood and "GLM-conjugate" models?

Suppose we have a response variable that represents proportions with a poorly defined denominator. Two ways to handle this (1) a quasibinomial model, which assumes only that the variance is ...
user avatar
1 vote
1 answer
68 views

How to deal with negative proportions in Dirichlet Regression

I am trying to work on a Dirichlet regression problem where I look at three true proportions the first two are actually measured while the third is computed as the complement: $$p_3=1-p_1-p_2$$ The ...
user avatar
0 votes
2 answers
298 views

Beta regression fitted values

I have a beta regression model in R, have generated predicted (fitted) values based on my data, and plotted lines of those fitted values on a scatter plot of the actual data. I'm most used to GLMMs, ...
user avatar
  • 1
0 votes
0 answers
114 views

Beta regression and post hoc test correct linear connectors?

I am trying to run a beta regression on my percent data which can be found here. My research question: How is percent cover changing in each transect over each event? Beta regression was choosen based ...
user avatar
3 votes
1 answer
202 views

Is a beta regression appropriate for a skewed bounded continuous dependent variable when sample size is small?

My data contain a bounded continuous variable (score between 0 and 10) representing the efficacy of a given method to control an invasive species. As there are more high scores than low ones, the ...
user avatar
  • 383
1 vote
0 answers
243 views

GLMMadaptive - Hessian matrix problem Hurdle Beta Model

Data: I have a percentage (or proportion see paragraph below) outcome dataset with a high number of zero's. I have therefore attempted to run a hurdle beta model using the GLMMadaptive package in R. I ...
user avatar
3 votes
0 answers
144 views

Improving fit of underdispered beta regression model in glmmtmb

I have survey data where the outcome is the proportion of a research budget interviewees wished to assign to one of three different "types" of research into solutions for various issues. I ...
user avatar
  • 31
4 votes
1 answer
79 views

Which regression model distribution or transformation for data bounded between -1 and 1?

It seems quite common in studies of plant interactions to find response variables that are bounded between -1 and 1, such as this relative interaction index (from Armas et al 2004, Ecology 85, https://...
user avatar
0 votes
1 answer
195 views

Is there an R package that runs frequentist zero-one inflated beta models? [closed]

I have a set of proportion data (below) with a many 1s. I would like to run a one inflated beta model in R, and want to use frequentest statistics. However the only zero-one inflated beta package I ...
user avatar
  • 673
4 votes
2 answers
1k views

Why is betareg() giving "invalid dependent variable" error?

I am trying to run a beta regression using the betareg package and I am using the following script: ...
user avatar
  • 673
2 votes
0 answers
170 views

Accounting for Spatial Autocorrelation in a GAM: including coordinates of points as smooth terms is not working

I have been trying to use GAM/GAMMs to account for spatial autocorrelation in residuals of a GLMM. I have explained my data in detail in this Stack Exchange question. The question also demonsrates how ...
user avatar
  • 91
1 vote
1 answer
58 views

Difference between t-test on betas from individual regressions vs linear mixed modeling

I often come across the following practice in my field; for example, people want to predict participants responses on a Dependent variable (e.g 0 or 1) based on a few independent variables - ...
user avatar
  • 119
1 vote
1 answer
332 views

Beta regression: Monte Carlo simulations for coefficients

I use betareg betaregresion to model degradation percentage over time: perc_degr~time. To calculate half-life (assuming logit ...
user avatar
  • 43
1 vote
1 answer
146 views

How can I calculate standardized weighted residuals 2 for a beta family glmm in R?

Hello and thank you for your time! I’m trying to calculate the "sweighted2" residuals for a beta family glmm with varying dispersion (aka precision parameter aka phi) fit using glmmTMB in R. ...
user avatar
  • 11
0 votes
1 answer
334 views

Modelling zero-inflated percentage data (vegetation cover) from single predictor variable

I am quite new to regression in R. I would like to analyse the relationship between 'Vegetation Cover'(response variable) and a single predictor variable 'Canopy Openness'. 'Vegetation Cover' is a ...
user avatar
  • 3
1 vote
1 answer
75 views

Correct distribution to model proportion of time in a day

I would like to determine how the presence of researchers influenced the amount of time that shorebirds spent on the nest in a day. My data consists of proportions that range from 0.715-0.997, which ...
user avatar
  • 71
0 votes
1 answer
220 views

Beta vs beta-binomial why beta has higher AIC

I am working with proportion data (very limited ~20 data points) for a response variable (RV), i.e. proportion of mature females out of total number of females sampled. The maturity is assessed by 6 ...
user avatar
2 votes
2 answers
178 views

best regression model for a percentage of function variable

I am trying to choose the best regression model for a dependent variable 'percentage of normal shoulder function'. This variable is non normal and clustered at the high end of the possible range, ie ...
user avatar