openintro (version 1.3)

prRace08: Election results for the 2008 U.S. Presidential race

Description

Election results for the 2008 U.S. Presidential race

Usage

data(prRace08)

source

Presidential Election of 2008, Electoral and Popular Vote Summary, collected on April 21, 2011 from

http://www.infoplease.com/us/government/presidential-election-vote-summary.html

Details

In Nebraska, 4 electoral votes went to McCain and 1 to Obama. Otherwise the electoral votes were a winner-take-all.

Examples

#===> Obtain 2010 US House Election Data <===#
data(houseRace10)
hr <- table(houseRace10[,c("abbr", "party1")])
nr <- apply(hr, 1, sum)

#===> Obtain 2008 President Election Data <===#
data(prRace08)
pr   <- prRace08[prRace08$state != "DC",c("state", "pObama")]
hr   <- hr[as.character(pr$state),]
(fit <- glm(hr ~ pr$pObama, family=binomial))

#===> Visualizing Binomial outcomes <===#
x  <- pr$pObama[pr$state != "DC"]
nr <- apply(hr, 1, sum)
plot(x, hr[,"Democrat"]/nr, pch=19, cex=sqrt(nr), col="#22558844",
    xlim=c(20, 80), ylim=c(0, 1), xlab="Percent vote for Obama in 2008",
    ylab="Probability of Democrat winning House seat")

#===> Logistic Regression <===#
x1 <- pr$pObama[match(houseRace10$abbr, pr$state)]
y1 <- (houseRace10$party1 == "Democrat")+0
g  <- glm(y1 ~ x1, family=binomial)
X  <- seq(0, 100, 0.1)
lo <- -5.6079 + 0.1009*X
p  <- exp(lo)/(1+exp(lo))
lines(X, p)
abline(h=0:1, lty=2, col="#888888")