# Questions tagged [logistic]

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

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### Unexpected singularities in the Hessian matrix error in multinomial logistic regression

I have been doing multinomial logistic regression analysis using SPSS 19. I have encountered the following problem when I run the analysis procedure: "Unexpected singularities in the Hessian ...
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### Predicting index from multiple predictors using panel data over 10 years: logit or probit? Fixed or random?

I am writing my master´s thesis in finance on the topic of voluntary disclosure of financial targets in annual reports of manufacturing firms. Context I have created a dependent variable that is an ...
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### Interpretation of odds ratio when outcome is a percentage

I ran a GEE model, with a dependent variable of "percent of total students with an unexcused absence," using a binomial family. My dependent variable is basically a proportion, with range from 0 to 1 ...
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### What does "20/ln(2)" mean in logistic regression?

I am trying to understand Logistic Regression in relation to credit scoring model. I wish to understand the significance of "20/ln(2)" in logistic regression. Why and how is it used?
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### How to handle categorical dependent variable using logistic regression when one of the categories never occurs in the sample

I have a multinomial logistic regression model. One of the output categories is not observed in the data set that I'm using. Example: 4 different diagnoses (response variable) in the population, ...
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### Multiclass logistic regression with mlogit in R

I have a multi-class dataset like the following (a,b,c,d are features and e is the class (it can be 0,1 and 2)). ...
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### How to perform logistic regression with lasso using GLMSELECT?

I am trying to perform logistic regression with lasso. For the logistic regression part I am using PROC LOGISTIC but I am not sure how to do lasso with ...
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### Binning raw data prior to building a logistic regression model

I have a set of variables for building credit scorecards with logistic-regression. I need to bin some variables, for e.g. years of credit history. What is the method to determine how many bins and ...
4k views

### Is a predictor with greater variance "better"?

I have a "basic statistics" concept question. As a student I would like to know if I'm thinking about this totally wrong and why, if so: Let's say I am hypothetically trying to look at the ...
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### What is the appropriate way to test for a shift in probability using multiple logistic regression?

We have data on the day in which a butterfly pupates (forms a cocoon) in the summer/fall of 2 different pairs of years (2005-2006 vs 2009-2010). At the time that the pupa forms it can either be in ...
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### How can I estimate the time at which 50% of a binomial variable will have transitioned?

I have the following data, representing the binary state of four subjects at four times, note that it is only possible for each subject to transition $0\to 1$ but not $1\to 0$: ...
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### Problem building multinomial logit model formula on huge data in R

I am attempting to build a Multinomial Logit model with dummy variables of the following form: The dependent variable represents 0-8 discrete choices. Dummy Variable 1: 965 dummy vars Dummy Variable ...
608 views

### How to model logistic regression with continuous predictor in Bugs?

Is it possible to use a continuous predictor in Bugs? The simplest way of doing this would be turning the size variable in alligators example from discrete to continuous. Both Winbugs and JAGS ...
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### How to set up and estimate a multinomial logit model in R?

I ran a multinomial logit model in JMP and got back results which included the AIC as well chi-squared p-values for each parameter estimate. The model has one categorical outcome and 7 categorical ...
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### How to carry out multiple post-hoc chi-square tests on a 2 X 3 table?

My data set is comprised of either total mortality or survival of an organism at three site types, inshore, midchannel and offshore. The numbers in the table below represent the number of sites. <...
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### Treating 'Don't know/Refused' levels of categorical variables

I am modeling Diabetes Prediction using Logistic Regression. The dataset used is the Behavioral Risk Factor Surveillance System (BRFSS) of the Center for Disease Control (CDC). One of the independent ...
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### Simultaneous Equation System for logit/probit?

Is it possible have an SES where the component equations are probabilistic, say, logit or probit? I am evaluating a number of quality metrics of services provided by a number of providers. The metrics ...
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795 views

### Using non-random sample to make population estimates

The health screening for immigration to the US includes a mandatory chest x-ray screening for all adults, with the aim of detecting signs of tuberculosis. If the x-ray indicates the possibility of TB,...
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### How can I assess GEE/logistic model fit when covariates have some missing data?

I have fit two generalized estimating equation (GEE) models to my data: 1) Model 1: Outcome is longitudinal Yes/No variable (A) (year 1,2,3,4,5) with longitudinal continuous predictor (B) for years 1,...
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### How can I correct for measurement error in the dependent variable in a logit regression?

I'm running a binary logit regression where I know the dependent variable is miscoded in a small percentage of cases. So I'm trying to estimate $\beta$ in this model: $prob(y_i) = 1/(1 + e^{-z_i})$ ...
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### Binomial data analysis with all 0 responses for some treatment groups

We have a series of experiments where we measure virus transmission to plants when exposed to virus-infected insects for different time periods, so all of the experiments have similar types of ...
4k views

### Comparing logistic coefficients on models with different dependent variables?

This is a follow up question from the one I asked a couple of days ago. I feel it puts a different slant on the issue, so listed a new question. The question is: can I compare the magnitude of ...
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### Comparing logistic regression coefficients across models?

I've developed a logit model to be applied to six different sets of cross-sectional data. What I'm trying to uncover is whether there are changes in the substantive effect of a given independent ...
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### Chi-squared versus logistic regression

I used summary.formula from Hmisc with continuous Age and binary outcome ...
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### Logistic Regression in R (Odds Ratio)

I'm trying to undertake a logistic regression analysis in R. I have attended courses covering this material using STATA. I am finding it very difficult to replicate ...
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### How to assess mediation effect in multinomial logistic regression? [closed]

I wonder if it possible to include a mediation effect in multinomial logistic regression. I have a categorical (3 categories) outcome variable and four predictors (all continuous). I expect one of the ...
130k views

### How to calculate pseudo-$R^2$ from R's logistic regression?

Christopher Manning's writeup on logistic regression in R shows a logistic regression in R as follows: ...
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### Analysis plan using logistic regression

I am researching age at first sexual debut and HIV prevalence in Lesotho. I want to analyse the data using logistic regression with SPSS. My variables are age, sex, social status, education level, ...
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### Logistic regression for bounds different from 0 and 1

I have some data; it's a proportion $y$ of some stuff relative to everything, so it's bounded between 0 and 1 by definition. The proportion changes over time. Besides fairly high variance there is a ...
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### Interpretation of log transformed predictors in logistic regression

One of the predictors in my logistic model has been log transformed. How do you interpret the estimated coefficient of the log transformed predictor and how do you calculate the impact of that ...
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### How to do logistic regression subset selection?

I am fitting a binomial family glm in R, and I have a whole troupe of explanatory variables, and I need to find the best (R-squared as a measure is fine). Short of writing a script to loop through ...
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### How to calculate the hat matrix for logistic regression in R?

I want to calculate the hat matrix directly in R for a logit model. According to Long (1997) the hat matrix for logit models is defined as: $$H = VX(X'VX)^{-1} X'V$$ X is the vector of ...
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### What is the significance of logistic regression coefficients?

I am currently reading a paper concerning voting location and voting preference in the 2000 and 2004 election. In it, there is a chart which displays logistic regression coefficients. From courses ...
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### How to choose number of dummy variables when encoding several categorical variables?

I'm building a logistic regression, and two of my variables are categorical with three levels each. (Say one variable is male, female, or unknown, and the other is single, married, or unknown.) How ...
383 views

### Discussing binomial regression and modeling strategies

Today I have got a question about binomial/ logistic regression, its based on an analysis that a group in my department have done and were seeking comments upon. I made up the example below to protect ...
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### How to understand output from R's polr function (ordered logistic regression)?

I am new to R, ordered logistic regression, and polr. The "Examples" section at the bottom of the help page for polr (that fits a logistic or probit regression ...
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### Analyzing a 2x3 repeated measures design using a logit mixed model

An experiment I conducted recently used a 2 (between participants) x 3 (within participants) design. That is, participants were randomly allocated to one of two conditions, and then completed three ...
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### Calculating predicted values from categorical predictors in logistic regression

Context: I am working with an ordinal logistic model and trying to interpret/present the results. The model has two continuous predictors of interests, and a mix of continuous and categorical ...
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### Interpreting significance of predictor vs significance of predictor coeffs in multinomial logistic regression

I have a multinomial logistic regression with dependent variable valued in {-1,0,1} (reference category is 0) and a number of continuous and discrete predictors. After running the regression a ...
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### Singular information matrix error in lrm.fit in R

I am running an ordinal logistic regression in R and running into trouble when I include dummy variables. My model works great with my first set of predictors. Next I want to add dummy variables for ...
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### How to use variables derived from factor analysis as predictors in logistic regression?

Context I have a survey that asks 11 questions about self-efficacy. Each question has 3 response options (disagree, agree, strongly agree). Nine questions ask about self-esteem. I have used a factor ...
1 vote
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### Entering variables in multivariate logistic regression and running regression across two groups

I am trying to do a multiple logistic regression for 2 similar groups. I have a few questions: In doing a univariate analysis, do I enter each independent variable, one at a time, first into the ...
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### How to decide between a logistic regression or conditional logistic regression?

I have a case-control study in which the cases are firms with health insurance and the controls are firms with no health insurance. I am studying the factors affecting enrolment in health insurance ...
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### How to obtain in R a good formula for glm (general linear models) to predict a binomial variable?

Is there a package or library that can help me suggest a formula given the independent variables which will work well in glm, for example this formula can be something like x^2+log(y)+Z, it does not ...
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### What does "case-control" and "cross-sectional" mean in the context of logistic modeling?

While studying logistic modeling, I read the following statement The fact that only odds ratios, not individual risks, can be estimated from logistic modeling in case-control or cross-sectional ...
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### How to do a logistic regression with the results of different factor analysis methods

I have a large amount of variables (24) to predict a Y/N value, and I would like help for writting a procedure that automatically tries the different results of the factor selection to see how good ...
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### Geostatistical analysis using spatial.exp in WinBugs

I have a logistic regression model in GeoBugs to estimate predictors of prevalence of a disease. Can anyone tell me if there is a simple way to determine the lower and upper bounds of phi for spatial....
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### Alternative ways for interpretation of odds

I am reading the second edition of Categorical Data Analysis by Alan Agresti, and somehow stuck in the following second paragraph: I don't quite understand why $\beta\pi(\hat{x})(1 - \pi(\hat{x}))$ ...
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