Questions tagged [logistic]

Refers generally to statistical procedures that utilize the logistic function, most commonly various forms of logistic regression

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340 views

Detecting collinearity in Logistic Regression model

I'm running a predictive model using the logistic model in SAS and, currently, I'm trying to perform some diagnostics about the collinearity issue in the estimated model. To do that, I followed step-...
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96 views

Can a random effects intercept variable be highly but coincidentally correlated to a response variable?

Issue- I'm creating a logistic mixed model where the response variable (if a plot falls within an active bird lek area) is highly related to a term I may include as a random effects term (grazing ...
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2k views

How to calculate odds ratio per unit decrease of continuous variable

I have a logistic regression model obtained in R comparing association between two index diagnoses (0 or 1) with Age (continuous) + ...
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48 views

Mismatch Between the Parameters of a Logistic Regression in R and My Computed Parameters

By converting and by trying to interpret the parameters of a logistic regression ran in R, I just find them to be overestimated. Therefore I tried to compute them myself but I can not obtain the same ...
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168 views

Sample size formula for multiple regression between binomial variables?

Let's say we have k binomial variables, and a sample size of n observations per variable, where each variable occurs (positive case) at a given frequency/probability f. We would like to check if ...
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127 views

How should I interpret/follow-up on mixed logistic regression (GLMM) diagnostics?

I have experimental data (n subjects = 64) in which the response variable, accuracy (0 or 1), was measured 9 times within subjects. My predictor is Condition (A vs B) measured between subjects. I ...
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851 views

Bootstrap logistic regression with rare events and rare outcomes and rare predictors

I am recently using bootstrap for statistical inference and confidence interval building in the setting of regression, especially logistic regression. In many works I've been doing I find that using ...
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1k views

Marketing/Sales Mix/Response Models: approaches and comparisons

CV/SO Community: I am probably skirting (or crossing) the line of the preference for questions that can be answered vs. those that can (only) be discussed. That said, I'm trying to wrap my head ...
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63 views

What is the best way to simultaneously fit multiple binomial and continuous predictors?

What is the most efficient way to fit a linear model w so that Y = w . X, where X is a ...
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506 views

R - CV.GLMNET LASSO (binomial) variable reduction - highly correlated variables not zeroing out

I have a dataset of about n = 100,000 observations and p = 247 predictors with one binomial dependent variable (values are 0, 1) I run the following code in R: ...
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675 views

Right-censored independent variable in Cox/logistic regression

I have a right-censored continuous independent variable that I want to include in a Cox regression. The variable is a physiologic test which is capped at a certain time, say 120 seconds, due to safety ...
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611 views

Handling singular matrix / linear separation in multinomial logit regression

I am doing an analysis of a choice-based conjoint / discrete choice experiment. After using the mlogit.data function in the ...
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96 views

Fisher's method for P-value more conservative than OLS?

I am currently observing an interesting phenomenon in my analysis. I have a simple logistic regression model for independent Inds. The model is as follows: $$\operatorname{logit}(Y) = \beta_0+\...
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754 views

Testing for Endogeneity in Logistic Regression

how can I test for endogeneity in logistic regression models? Possibly off the track: I used VIF to test for multicollinearity which, however, I read is also a possible sign for endogeneity.
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380 views

Variable correlation and collinearity in logistic regression

Hoping to get some insight on the issue of correlation/collinearity in predictors for logistic regression. Let me preface this by saying I’m no statistician, but rather a GIS analyst with exposure to ...
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1answer
442 views

Ensembling Logistic Regressions Fit on Different Datasets

I would like to predict a binary response variable $Y_i$ using sets of predictors $\textbf{X}_{1i}, \textbf{X}_{2i}, \textbf{X}_{3i}$ for $i=1,\dots,n$. Each $\textbf{X}$ contains a few dozen ...
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821 views

Correcting for heteroscedasticity in logistic regression

I am using a large health dataset as a part of a research project (N = ~18 000). My colleagues and I are investigating whether smoking predicts the presence or absence of a mental illness. We are ...
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9k views

How many degrees of freedom in logistic regression?

I did an experiment where 1600 people either responded (1) or not (0) to 4 treatments (400 unique people per treatment): ...
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82 views

Estimation Procedure of Multilevel Logistic Regression

I know the estimation procedure for logistic regression is the iterative weighted least squares method. In the book An Introduction to Generalized Linear Models written by Dobson & Barnett, in ...
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365 views

Fitting logistic growth model. lme4 or nlme?

This is the first time I am using a nonlinear model. I am using a logistic growth model for analyzing tree growth pattern given by M. Bates and Pinheiro, 2000:. $$ y = \frac{\phi_1}{1+e^{-(x-\phi_2)...
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904 views

Censored logistic regression

I have the following problem: We have data with a 0-1 outcome which can occur precisely once. It can occur at any time within a certain time period (say 3 years). For this data set, for some ...
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262 views

In feature engineering, is using x*y as an interaction term different from using x/y?

I want to engineer some new features for a classifier, say, logistic regression. Let's say I have two continuous (numeric) features $x$ and $y$. I know that you can create a new feature from $x$ and $...
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93 views

Logistic Regression Model with Non-Independent Regressors

I'm looking to create a model that takes into account multiple logistic variables in an ordered process. To illustrate, what I'm trying to do is similar to the following: ...
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183 views

Appropriate test (in R) for proportion data that aren't normally distributed, aren't based on counts, and include 0's and 1's?

I'm studying differences in tree health among 5 species of trees across 3 different green infrastructure types. Here are the first few lines of data: ...
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171 views

Does conditional logistic regression effectively “throw away” concordant pairs like McNemar's test?

We are interested in analyzing pre-post data from a randomized control trial. The outcome is binary and I am trying to explain the heuristics of the model formulation for conditional logistic ...
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1answer
840 views

estimate conditional distribution from data

I have a dataset defined by 2 variables ...
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417 views

heteroskedasticity in logit/cox

I am using a logit and a cox proportional hazard model for my analysis, and the newest version of Stata. I have found that there are no tests to check for heteroskedasticity for logit/probit models, ...
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449 views

How to calculate the standard error of an odds ratio from the standard error of two logits?

For example, given two logits and their standard errors: Logit = -3.1435, SE = 1.6847 Logit = -2.7581, SE = 0.9081 I can calculate the odds ratio to be exp(-2.7581 - -3.1435) = 1.47, but is there a ...
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623 views

Marginal effect calculation after logistic regression with panel dataset using R

I would like to perform a logit regression with a panel dataset, I know that the pglm package does the job, however, does anyone know if there is a standard package in R that allows me to calculate ...
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119 views

Discrete Choice Models

For multinomial (or mixed) logit models, when the choice set is too large, either strategic sampling or random sampling of the choice set can be used. My question is: Is that also true for panel data ...
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711 views

Diagnostics for multinomial and ordinal regression models

In the case of a binary outcome and a number of explanatory variables, logistic regression can be used and a number of diagnostic tools can be applied to assess the relative (e.g. AIC, if one wishes ...
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196 views

Motivating likelihood ratio test vs Wald test for paper reviewer

I've got back reviews for a paper I've submitted, with the following problem. I have two logistic regression models, say y ~ A, and y ~ A + B, where B is a factor with several levels. I have ...
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124 views

Use of Deviance Residuals for Leave-One-Out Cross Validation

I am a newbie to stats and having some difficulties understanding how to use deviance residuals for leave-one-out cross validation for a logistic regression model. The problem that I am trying to ...
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142 views

What is the “Logistic Regression”? I cannot have a unified concept

I'm interested in logistic regression for modeling a classification problem. I tried to study logistic regression with two books, "Discrete Choice Methods with Simulation" (Train) and "Applied ...
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201 views

theoretical concerns in logistic regression

I have a dataset with 260 patients. I aim to study factors associated the certain finding in magnetic resonance imaging. I use logistic regression with six predictors. Regression yields to several ...
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284 views

Mediation on an interaction with dichotmous mediator

We are using Tingely et al's mediation R package for mediation analysis. Our study is a 2x2 design, say A (0 and 1) and B (0 and 1), with dichotomous mediator M and continuous dependent measure Y. Our ...
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103 views

What is the posterior probability of the data given the model used for model averaging with Bayesian Logistic Regression?

I am trying to learn about Bayesian Model Averaging using Bayesian Logistic Regression (Genkin, A., Lewis, D. D., & Madigan, D. (2007). Large-scale Bayesian logistic regression for text ...
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262 views

How to select the exponential decay constant for weighting in proc logistic?

I am trying to predict the sales conversion using proc logistics in SAS. Right now I have around 3 months of data, and it will gradually grow to more than an year over time. My intuition is that the ...
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63 views

How to model continuous predictor variable, $x\ge0$, showing continuity “jump” at $x=0$?

I'm modeling hospital inpatient stays with a logistic regression model, and have encountered a number of predictor variables measuring # of outpatient care episodes which have an inflated number of ...
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101 views

Logistic Regression not quite working

I'm playing around with logistic regression (using scikit-learn, which uses liblinear) I created some example data sets, and it often works well. Since I created the data sets, I already know the ...
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755 views

What does “Fama-MacBeth logit regressions” mean?

On page 10 of this paper the author states that In this section, I use monthly Fama and MacBeth (1973) logit regression [...] to examine the type of forecast. My question(s) are: what does ...
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2k views

How to interpret chi-squared test for main effect in presence of interaction term

I have run a sequence of nested multi-level models using lmer, and looked at both the summary output giving all the coefficients, etc, as well as the Anova output which does a chi-squared test on each ...
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2k views

How do I calculate confidence intervals for a linear combination of coefficients of a logistic regression?

I want to test a series of hypotheses on linear combinations of coefficients for logistic regression on categorical count data implemented as a GLM model. I know how to do linear combinations under ...
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511 views

How can I simulate data for comparing logit and probit model?

Can anybody tell me how can I simulate a data set for comparing logit and probit model? If I simulate a data from a standard multivariate normal distribution considering 5 variables then can I use ...
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2k views

Interpreting Coefficients from Logistic Mixed Effects Model

I am trying to use glmer to create logistic mixed effects models (LMEMs) and then run a model comparison between them. Respondents can click "Yes" (coded as 1) or "No" (0), which is used as the DV. ...
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414 views

Fractional Polynomial interpreting interaction terms

Background: I have developed a logistic regression model where I am trying to analyze the effect of socio-economic data of a family on their probability of receiving a home loan. I have used ...
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4k views

Proportion data: - beta regression or logit transformed OLS regression?

I have proportion data (percentage viewership of TV programs) that i'd like to model as a function of various demographics (age, sex etc.) and time (year). After surveying options for appropriate ...
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265 views

Role of coefficients in model selection for logistic regression

I have a model that I am using to predict mortality and it gives me an AUC of 0.799. The R code that I am using would look something like this: ...
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1k views

Marginal effect clogit not significant

I developed a conditional logit model in Stata. The model is good and the variables are highly significant. Then I do mfx predicted (PU0) to determine the marginal effects of variables $\frac{dy}{dx}$....
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1k views

Variable selection / Dataset reduction for large datasets (in R)

I'm working on a behavioral scorecard modelling exercise, and many of the decisions taken to date have been based on the experience of a consulting credit analyst (whose experience software-wise is ...

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