longley               package:datasets               R Documentation

Longley's Economic Regression Data

Description:

     A macroeconomic data set which provides a well-known example for a
     highly collinear regression.

Usage:

     longley

Format:

     A data frame with 7 economical variables, observed yearly from
     1947 to 1962 (n=16).

     GNP.deflator: GNP implicit price deflator (1954=100)

     GNP: Gross National Product.

     Unemployed: number of unemployed.

     Armed.Forces: number of people in the armed forces.

     Population: 'noninstitutionalized' population >= 14 years of age.

     Year: the year (time).

     Employed: number of people employed.

     The regression 'lm(Employed ~ .)' is known to be highly collinear.

Source:

     J. W. Longley (1967) An appraisal of least-squares programs from
     the point of view of the user. _Journal of the American
     Statistical Association_, *62*, 819-841.

References:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

Examples:

     require(stats); require(graphics)
     ## give the data set in the form it is used in S-PLUS:
     longley.x <- data.matrix(longley[, 1:6])
     longley.y <- longley[, "Employed"]
     pairs(longley, main = "longley data")
     summary(fm1 <- lm(Employed ~ ., data = longley))
     opar <- par(mfrow = c(2, 2), oma = c(0, 0, 1.1, 0),
                 mar = c(4.1, 4.1, 2.1, 1.1))
     plot(fm1)
     par(opar)

