data slid1 ; infile 'c:\temp\SLID-Ontario.txt' firstobs = 2 delimiter = '09'x ; input age sex $ wages yearsed ; male = (sex eq 'Male') ; log2wages = log2(wages) ; obs = _n_ ; title 'SLID data'; run ; proc print data = slid1 (obs = 10) ; run ; * ---------------------------------------------------------------------; * Demonstrating different variance estimators ; * ---------------------------------------------------------------------; proc reg data = slid1 ; model wages = male age yearsed ; run ; proc reg data = slid1 ; model wages = male age yearsed / hcc hccmethod=0 ; * original White estimator ; run ; proc reg data = slid1 ; model wages = male age yearsed / hcc hccmethod=3 ; * modified White estimator supported by Long and Ervin ; run ;