longley {base}R Documentation

Longley's Economic Regression Data

Description

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

Usage

data(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

## give the data set in the form it is used in S-PLUS:
data(longley)
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)

[Package Contents]