* PS8.3, using DATA8-1, for Example 8.4, Goldfeld-Quandt test read(data8-1) SALARY YEARS genr LNSALARY=log(SALARY) genr YRS2 = YEARS*YEARS * estimate log quadratic model for first 75 observations smpl 1 75 ols LNSALARY YEARS YRS2 * estimate log quadratic model for last 75 observations smpl 148 222 ols LNSALARY YEARS YRS2 * compute F-statistic and pvalue for test smpl 1 222 gen1 Fc=0.050608/0.015416 distrib Fc / type=F df1=72 df2=72 stop