* Use 401KSUB.dta generate age_25sq = (age - 25)^2 keep if fsize==1 * The first OLS regression reported in Table 8.1 regress nettfa inc * BP test for heteroskedasticity estat hettest * Plot the residuals as a function of inc rvpplot inc, yline(0) scheme(lean1) * The second OLS regression reported in Table 8.1 regress nettfa inc age_25sq male e401k * BP test for heteroskedasticity estat hettest * Plot the residuals as a function of inc rvpplot inc, yline(0) scheme(lean1) generate weight = 1/inc^0.5 generate constar = 1*weight generate incstar = inc*weight generate nettfastar = nettfa*weight * First WLS reported in Table 8.1 regress nettfastar constar incstar, noconstant generate age_25sqstar = age_25sq*weight generate malestar = male*weight generate e401kstar = e401k*weight * Second WLS reported in Table 8.1 regress nettfastar constar incstar age_25sqstar malestar e401kstar, noconstant * WLS with Robust Standard Errors as reported in Table 8.2 regress nettfastar constar incstar age_25sqstar malestar e401kstar, noconstant robust