*  PS6.1 using data file DATA4-1, for Example 6.1
SAMPLE 1 14
READ(data4-1) PRICE SQFT BEDRMS BATHS
*
* Estimate the best Linear Model.
*
OLS PRICE SQFT 
*
* Estimate the best Linear-Log Model.
*
* The GENR command creates new variables and performs a variety of 
* transformations on existing ones.  In this case, the GENR command is used
* to generate the natural logs of the variables SQFT and BEDRMS.
*
GENR LNSQFT=LOG(SQFT)
GENR LNBEDRMS=LOG(BEDRMS)
GENR LNBATHS=LOG(BATHS)
*
* The LINLOG option must be specified on the OLS regression since the
* dependent variable, PRICE, is in linear form and the independent
* variables, LNSQFT and LNBEDRMS, are in log form.  If this option is
* not specified then the elasticities from the OLS regression will not
* be estimated correctly.
*
OLS PRICE LNSQFT LNBEDRMS LNBATHS / LINLOG
OLS PRICE LNSQFT LNBEDRMS / LINLOG
OLS PRICE LNSQFT / LINLOG
DELETE / ALL
STOP