Monthly US retail gasoline price (the average price per gallon, in dollars) and the spot price of a barrel of West Texas Intermediate (WTI) oil in dollars as traded at Cushing, Oklahoma. Jan 1991 - Nov 2006.
Source
Hyndman, R.J., Koehler, A.B., Ord, J.K., and Snyder, R.D., (2008) Forecasting with exponential smoothing: the state space approach, Springer.
References
http://www.exponentialsmoothing.net. These series are available from the US Energy Information Administration website http://www.eia.doe.gov.
Examples
par(mar=c(5,4,2,5))
plot(gasprice[,1], xlab="Year", ylab="Average retail price per gallon (dollars)",
main="Gasoline and oil prices")
par(new=TRUE)
plot(gasprice[,2], col="blue", xaxt="n", yaxt="n", xlab="", ylab="")
axis(4)
mtext("Spot price per barrel (dollars)", side=4, line=3)
legend("topleft", col=c("black","blue"), lty=1,
legend=c("Ave retail price of gasoline", "Spot price of WTI oil"))
