FitAR (version 1.94)

USTobacco: U.S. Tobacco Production, 1871-1984

Description

Annual U.S. tobacco production, 1871-1984, in millions of pounds.

Usage

data(USTobacco)

Format

The format is: Time-Series [1:114] from 1871 to 1984: 327 385 382 217 609 466 621 455 472 469 ... - attr(*, "title")= chr "Tobacco production,US, 1871-1984"

Source

Wei, W.W.S. (2006, Series W6, p.570), Time Series Analysis: Univariate and Multivariate Methods. 2nd Ed., New York: Addison-Wesley.

Details

Wei (2006, p.120, Example 6.6) fits an ARIMA(0,1,1) to the logarithms. But a more accurate Box-Cox analysis indicates a square-root transformation should be used. A more complex ARIMA-GARCH model is also suggested by Wei (2006).

Examples

#From a plot of the series, we see that the variance is increasing with level.
#From the acf of the first differences an ARIMA(0,1,1) is suggested.
 data(USTobacco)
# layout(matrix(c(1,2,1,2),ncol=2))
 plot(USTobacco)
 lines(lowess(time(USTobacco), USTobacco), lwd=2, col="blue")
 acf(diff(USTobacco, differences=1))