*
* Example 10.3 from page 337
*
cal 1950
open data prminwge.raw
data(org=columns) 1950:1 1987:1 year avgmin avgwage kaitz avgcov covt mfgwage prdef $
  prepop prepopf prgnp prunemp usgnp trend post74 $
  lprunemp lprgnp lusgnp lkaitz lprun_1 lprepop lprep_1 mincov lmincov lavgmin
*
linreg lprepop
# constant lmincov lusgnp