An incomplete example of how to use predicted probabilities to be completed in class.

logit-qi-incomplete-example.R

# load libraries
library(arm)

# read data
d <- read.csv("http://crain.co/am-files/data/turnout-small.csv")

# estimate simple logit model
m <- glm(vote ~ educate + age + income, 
         family = binomial, data = d)

# display results
display(m, detail = TRUE)

# what are the distributions of these variables?
par(mfrow = c(1, 3))
hist(d$educate)  # in years
hist(d$age)  # in years
hist(d$income)  # in 10,000s of dollars

# what are the medians of these variables?
median(d$educate)  # in years
median(d$age)  # in years
median(d$income)  # in 10,000s of dollars