Is there any way to fit a `glm()` so that all levels are included (i.e. no reference level)?

Question

Consider the code:

x <- read.table(\"http://data.princeton.edu/wws509/datasets/cuse.dat\",
                header=TRUE)[,1:2]

fit <- glm(education ~ a         


        

Answer 1

You'll want to use the model.matrix function to convert the factors in the age variable to binary variables.

See this answer.

EDIT: Here is an example:

x <- read.table("http://data.princeton.edu/wws509/datasets/cuse.dat",
                header=TRUE)[,1:2]
binary_variables <- model.matrix(~ x$age -1, x)
fit <- glm(x$education ~ binary_variables, family="binomial")
summary(fit)