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
10 votes
1 answer
3k views

Logit transformation or beta regression for proportion data

I'm interested in knowing about the difference in interpretation between (1) linear regression on a logit transformed variable with values between 0 and 1 and (2) beta regression where the values ...
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 – ...
1 vote
1 answer
444 views

How do I interpret a betareg coefficient of 6.6970 for a categorical variable with only two categories, given that the response is a proportion?

I cannot seem to find an exact answer to my question online. I used the betareg package in R to run a glm with a response variable that is a proportion, so it is between 0 and 1. One of my predictor ...
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 ...
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: ...
4 votes
1 answer
3k views

Appropriate GLM for proportion response variable

I have a dataset that includes the number of apples harvested from 31 trees and the number of apples from each tree affected by different forms of pest damage. I also have insect abundance data (...
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. ...
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 <...
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 ...
0 votes
1 answer
252 views

Attempting to interpret both Beta Regression and transformed DV model results

After reading a good amount of the answered questions on interpreting Beta Regression results (Best explanation here) and reading through the Betareg vignette, I still feel a lack of confidence ...
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 ...
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, ...
0 votes
2 answers
299 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, ...
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(...
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 ...
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 ...
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 ...
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 ...
2 votes
1 answer
617 views

Can distributions that are in the exponential family, but not the natural exponential family, be formed as GLM?

The lognormal and beta distributions are in the exponential family but not the natural exponential family. Generalized Linear Models are often advertised as being models for response variables that ...
0 votes
2 answers
116 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 ...
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 ...
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: ...
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?...
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 ...
2 votes
0 answers
784 views

beta regression creating a wild residual vs. fitted plot- whats going on?

I recently ran a beta regression model in R using the betareg package. I am modeling a continuous dependent variable (a fraction out of 1) that is bound between 0 ...
2 votes
1 answer
428 views

Standardized beta on standardized variables

I am having trouble understanding why the standardized beta option in regress in Stata gives me different results when I ...
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 ...
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 ...
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 ...
16 votes
4 answers
13k views

How to implement a mixed model using betareg function in R?

I have a dataset comprised of proportions that measure "activity level" of individual tadpoles, therefore making the values bound between 0 and 1. This data was collected by counting the number of ...
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 ...
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 ...
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 (...
3 votes
0 answers
1k views

What is Mu in zero/one beta inflated models? (gamlss (BEINF))

I am estimating a zero/one inflated beta regression model with gamlss (family BEINF). My dependent variable is [0,1] with a lot of 0s, quite some 1s, and some values in between. This means I assume ...
11 votes
0 answers
1k views

Negative deviance explained by GAM with betareg in R

I am fitting the following model in "mgcv" package in R using option family=betar to predict a percentage cover response variable (...
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 ...
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?
23 votes
5 answers
11k views

Dealing with 0,1 values in a beta regression

I have some data in [0,1] which I would like to analyze with a beta regression. Of course something needs to be done to accommodate the 0,1 values. I dislike modifying data to fit a model. also I ...
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 ...
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 ...
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 ...
11 votes
2 answers
3k views

What's a time series model for forecasting a percentage bound by (0,1)?

This must come up---the forecasting of things that are stuck between 0 and 1. In my series, I suspect an auto-regression component, and also a mean-reverting component, so I want something that I can ...
1 vote
1 answer
2k views

Is an overdispersion parameter of 5.17 for GLMM with Beta family too high to yield reliable results?

I'm running a generalised linear mixed model with beta family on the effect of overhead cover (proportion ∈ (0,1)) on the proportion of birds scavenging from carrion left out in nature (proportion ∈ (...
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' ...
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 ...
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 ...
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_% ...
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 ...
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 ...
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 ...