# Equally spaced ordinal outcome in regression

If in a multiple regression model I have an ordinal dependent variable I have to use ordinal logistic regression. In particular, I have to do that if the distance between ordinal output is not equally spaced.

For instance if the outcome variable is size of soda, small-medium-large, the difference between the various sizes is not consistent. The difference between small and medium is 10 ounces, between medium and large 8.

What if the "distances" among ordinal outcomes are consistent (equally spaced)? Can I use the multiple linear regression in that case? I guess not, but I wanted to check.

• This question seems to use the term "ordinal" as if it meant interval. By definition, there is no "distance" between ordinal outcomes. – whuber Nov 5 '14 at 17:25