Hi !
This is Madhavi from Mumbai, India. Incidently this is my first post.
I am working on Credit Scoring Model and using R, I have run the logistic
regression. I have received following Output.
I have two questions
(a) What is the significance of "family = binomial(link = logit)". Why
do I have to mention Binomial? Is it because my dependent variable assumes only
two values 0 and 1? Can I write name of some other Statistical distribution (say
Poisson or Negative Binomial) in place of Binomial? How will it affect my
results?
(b) How do I interpret the "R" result as given below? I know all the
variables are significant. How do I get Log Likelihood ratio, Odds ratio etc.?
Please can anyone help me out.
With warm regards
Madhavi
R OUTPUT
Call:
glm(formula = Y ~ Age1 + Age2 + Sex + Education + Profession + SavingsAccount +
CurrentAccount, family = binomial(link = logit), data = ons)
Deviance Residuals:
Min 1Q Median 3Q Max
-3.21142 -0.42556 -0.15911 -0.02954 3.02465
Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept) 2.627725 0.110752 23.726 < 2e-16 ***
Age1 0.692180 0.070410 9.831 < 2e-16 ***
Age2 -2.817883 0.080801 -34.874 < 2e-16 ***
Sex -0.486132 0.049766 -9.768 < 2e-16 ***
Education -0.682142 0..046507 -14.667 < 2e-16 ***
Profession -0.690937 0.069032 -10.009 < 2e-16 ***
SavingsAccount -1.891455 0.074906 -25.251 < 2e-16 ***
CurrentAccount -1.367460 0.079604 -17.178 < 2e-16 ***
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
(Dispersion parameter for binomial family taken to be 1)
Null deviance: 26932 on 24999 degrees of freedom
Residual deviance: 14615 on 24983 degrees of freedom
(2 observations deleted due to missingness)
AIC: 14649
Number of Fisher Scoring iterations: 6
Unlimited freedom, unlimited storage. Get it now, on
http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/
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Em Qua, 2008-08-20 ?s 23:54 -0700, Madhavi Bhave escreveu: Hi Madhavi,> Hi ! > > This is Madhavi from Mumbai, India. Incidently this is my first post.You are wellcome!> > I am working on Credit Scoring Model and using R, I have run the logistic regression. I have received following Output. > > I have two questions > > (a) What is the significance of "family = binomial(link = logit)". Why do I have to mention Binomial? Is it because my dependent variable assumes only two values 0 and 1? Can I write name of some other Statistical distribution (say Poisson or Negative Binomial) in place of Binomial? How will it affect my results?Well the logistitc regression is a generalized linear model. Your specification is just "binomial" function with "logit" link function so "summary" mention this especification ... The binomial model is choose because your data have a thorical binomial distribution (two type of outcome wtih fix probabilty of outcome and independent observations) For ohert distribuitions existing other links functions see more details in: ?family> > (b) How do I interpret the "R" result as given below? I know all the variables are significant. How do I get Log Likelihood ratio, Odds ratio etc.?well odds ratio: model<- glm (formula,family=binomial) exp(coef(model)) Log Likehood model$deviance -- Bernardo Rangel Tura, M.D,MPH,Ph.D National Institute of Cardiology Brazil