What’s the Best R-Squared for Logistic Regression?
One of the most frequent questions I get about logistic regression is “How can I tell if my model fits the...
Feb 13, 2013
Everybody’s Gonna Have a Number
This month I’m going to take a break from statistical methods and focus, instead, on a particular statistic: citation counts. Recently...
Jan 07, 2013
Why Learn Syntax?
One of the reasons so many people choose SPSS for data analysis is that it is quite simple to use, with...
Dec 03, 2012
Why You Probably Need More Imputations Than You Think
Over the last decade, multiple imputation has rapidly become one of the most widely-used methods for handling missing data. However, one...
Nov 09, 2012
How Relevant is the Independence of Irrelevant Alternatives?
When researchers estimate multinomial logit models, they are often advised to test a property of the models known as the independence...
Oct 08, 2012
When Can You Safely Ignore Multicollinearity?
Multicollinearity is a common problem when estimating linear or generalized linear models, including logistic regression and Cox regression. It occurs when...
Sep 10, 2012
Do We Really Need Zero-Inflated Models?
For the analysis of count data, many statistical software packages now offer zero-inflated Poisson and zero-inflated negative binomial regression models. These...
Aug 07, 2012
Why Maximum Likelihood is Better Than Multiple Imputation
I’ve long been an advocate of multiple imputation for handling missing data. For example, in my two-day Missing Data seminar, I...
Jul 09, 2012
Beware of Software for Fixed Effects Negative Binomial Regression
If you’ve ever considered using Stata or LIMDEP to estimate a fixed effects negative binomial regression model for count data, you...
Jun 08, 2012
Logistic Regression for Rare Events
Prompted by a 2001 article by King and Zeng, many researchers worry about whether they can legitimately use conventional logistic regression...
Feb 13, 2012