*
* Example 8.6 from page 273
*
open data saving.raw
data(format=free,org=columns) 1 100 sav inc size educ age black cons
*
* OLS
*
linreg sav
# constant inc
*
* WLS. With RATS, this is done using the SPREAD option on the LINREG. The spread
* indicates series to which the variances are proportional. In this case, that's
* the savings series. Note, by the way, that RATS reports the R**2 using the
* original levels for the data, not the rescaled values, so they won't match
* those shown in the text.
*
linreg(spread=inc) sav
# constant inc
*
* Same pair with extra explanatory variables
*
linreg sav
# constant inc size educ age black
linreg(spread=inc) sav
# constant inc size educ age black