Longley's 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 \ge 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.

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)