GET FILE='U:\)Research\ISSP20072008\issp_2007_2008nl_def.sav'. desc age gender z06a1 z34a. freq z06a1 z34a. recode z34a (1=0)(2=400)(3=800)(4=1150)(5=1450)(6=1750)(7=2150)(8=2700)(9=3500)(10=4500)(11=5500) into pinc. recode age (25 thru 34=30)(35 thru 44=40)(45 thru 54=50)(55 thru 64=60) into agecat. recode z06a1 (1 2 3 6=0)(4 5 7=1)(8 9=2) into educat. add value labels educat (0) Low (1) Medium (2) High. select if (educat ge 0). select if (age ge 25 and age le 64). select if (pinc ge 0). cross educat by agecat. means pinc by female by educat by agecat . ** HOW REGRESSION CONTROLS**. REGR /DEP=PINC /ENTER=AGECAT EDUCAT. ** RESIDUALIZING ** REGR /DEP=AGEcat /ENTER=EDUCAT /SAVE=RESID(AAA). REGR /DEP=EduCAT /ENTER=AGECAT /SAVE=RESID(EEE). corr pinc agecat educat aaa eee. REGR /DEP=PINC /ENTER=AAA. REGR /DEP=PINC /ENTER=EEE. ** NONLINEAR REGRESSION **. COMP PINC=PINC/100. graph /line(multiple) =mean(pinc) By age. regr /dep=pinc /enter=age /SAVE=PRED(X1). graph /line(multiple) =mean(pinc) MEAN(X1) By age. ** CREATING POLYNOMIAL TERMS **. comp age2=(age-40)**2. COMP age3=(AGE-40)**3. regr /dep=pinc /enter=age /enter=age2 /save=pred(QUAD). graph /line(multiple) =mean(pinc) MEAN(X1) MEAN(QUAD) By age. regr /dep=pinc /enter=age /enter=age2 /ENTER=AGE3 /save=pred(CUBIC). graph /line(multiple) =mean(pinc) MEAN(X1) MEAN(QUAD) MEAN(CUBIC) By age. means pinc quad cubic by age /cells=mean. ** SPLINE REGRESSION **. comp age1=age. comp age2=0. comp age3=0. comp age4=0. if (age ge 30) age2=age-30. if (age ge 40) age3=age-40. if (age ge 55) age4=age-55. graph /line(multiple) = mean (age3) mean(age2) mean(age1) by age. regr /dep=pinc / enter=age1 age2 age3 age4 /save=pred(ppp). graph /line(MULTIPLE)=mean(ppp) mean(cubic) MEAN(PINC) by age.