Linked Questions

16
votes
1answer
8k views

Understanding complete separation for logistic regression [duplicate]

Why does logistic regression not converge for a linearly separable data set? For linear separable data sets the model parameters go to infinity when mimizing the error function (according to ...
-1
votes
1answer
824 views

Logistic Regression: p values all '1', yet model fits perfectly [duplicate]

I was trying to help a student and was foxed by this Logistic Regression problem and seek your explanation. Here's some economic data. All we have to do is create a model to predict whether the ...
1
vote
1answer
3k views

Large value of exp (B) in binary logistic regression SPSS what is wrong? [duplicate]

I had a very large value for Exp(B) in SPSS binary logistic regression. What is wrong and what should I do?
4
votes
1answer
553 views

How to tell which variable is perfectly separated in R [duplicate]

I am running a logistic regression model in R using glm. I received a warning that complete separation occurred. How do I determine which variable is causing this? R doesn't tell you what variable is ...
2
votes
0answers
532 views

Logistic regression in R ; glm.fit: fitted probabilities numerically 0 or 1 occurred [duplicate]

I'm fitting a logistic regression model in R. Following is the structure of my data set. I've used the glm function in R. ...
1
vote
0answers
366 views

How to deal with separation in logistic regression? [duplicate]

I'm running a binary logistic regression on 15 independent variables for 180 observations in Stata (version 11). This I do for four different groups, i.e. four dependent variables. For three, it works ...
2
votes
0answers
138 views

Large coefficients in logistic regression [duplicate]

This is from the book The statistical sleuth--A course in methods of Data analysis Chapter 20, Exercise 12(c)-(e). I am using logistic regression to predict carrier with possible predictors ...
0
votes
0answers
111 views

How to deal with a model that can't be fit due to quasi-complete separation? [duplicate]

I am doing a binary logistic regression analysis. I got one categorical predictor with 7 levels. When I try to do this in Minitab 17 I get an error message: "The model could not be fit. Maximum ...
1
vote
0answers
96 views

logistic regression - complete/quasi-separation [duplicate]

What is the implication if I don't fix a logistic regression that has complete or quasi separation? can I still read the marginal effects or are they not going to be valid? My exercise is actually ...
0
votes
0answers
75 views

binomial GLM output hugely affected by a factor level with all zeros [duplicate]

I’m trying to estimate the effects of pest control on rat abundance, but I'm finding that the inclusion of a pest control category that contains all zeros is having huge effects on the results. My ...
1
vote
0answers
67 views

Logistic Regression Get 100% R-square but no predictors are significant? [duplicate]

How could that be possible? The model is significant too. The null model already predicted 70% correctly. After adding predictors, the model predicts 100%. But no single predictors are significant. I ...
1
vote
0answers
47 views

extremely strange logistic regression results [duplicate]

I am very new to r and statistics so excuse me if the answer to my question is very obvious. I have surveyed 64 people on their Facebook behaviour related to their political participation. One of my ...
1
vote
0answers
31 views

Problem with one variable in a binary logistic regression [duplicate]

I analyzed four binary variables with a binary logistic regression. I used for the analysis of all four binary y-variables the same set of 9 x-variables (a-i). My problem deals with one of this four ...
1
vote
0answers
28 views

Values distribution issue in logistic regression [duplicate]

I have a problem with logistic regression. I have the following variables: Var1: 1 1 1 0 0 1 1 1 1 1 1 1 1 0 1 0 0 1 1 1 1 1 1 1 1 0 0 NA 1 0 0 1 0 1 1 0 0 0 1 1 0 0 1 1 1 0 1 0 1 1 1 1 1 1 1 1 0 1 ...
0
votes
0answers
24 views

Is it ok to have “fitted probabilities numerically 0 or 1 occurred” in the case of predicting disease? [duplicate]

I know this isn't directly related to statistics but I didn't know where else I should post this so please let me know and I will remove the question if this is the wrong forum. My question is very ...

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