

   LLoonngglleeyy''ss RReeggrreessssiioonn DDaattaa

        data(longley)

   FFoorrmmaatt::

        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 Producr.
         Unemployed  :      number of unemployed
         Armed.Forces:      number of .. 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.

   SSoouurrccee::

        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.

   EExxaammpplleess::

        # 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"]

