Logistic Regression Using SAS®: Theory and Application

6.2. Cumulative Logit Model: Example

The cumulative logit model (McCullagh 1980) could hardly be easier to implement in SAS. Whenever PROC LOGISTIC encounters more than two categories on the dependent variable, it automatically estimates a cumulative logit model. Let’s try it and see what we get. Then we’ll step back and discuss the underlying model.

In Chapter 5, we analyzed data in which the dependent variable was the response to the question, “If you found a wallet on the street, would you (1) keep the wallet and the money, (2) keep the money and return the wallet, or (3) return both the wallet and the money.” Although we treated these response categories as unordered, there’s also an obvious ordering: 1 is the most unethical response, 3 ...