1. 用图表检验Analyze -> regression -> Linear-> Plots
" Q8 T6 G5 j uScatter plot of the standardised residuals on the standardised predicted values (ZRESID as the Y variable, and ZPRED as the X variable/ {# ]; t- k4 S$ B1 P8 h
2 S& Q0 t9 p4 K+ |/ C( \如果图表显示有可能存在异方差,需要用统计检验来进一步检测异方差是否确实存在。0 w' v% q9 [( F9 M& x6 P% y
2. 用统计检验, ~4 i9 P+ b7 A4 ?$ Y
Heteroscedasticity——Testing and Correcting in SPSS.pdf
Gwilym Pryce March 2002.doc
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Levene’s Test5 r4 l. V" A) s. ]
Goldfeld-Quandt Test' P$ {' P( }3 W. J1 w& G a; Y
Breusch-Pagan Test( l7 v P4 o* o
White‘s Test (比较常用来检验异方差)
8 d+ @0 W& m, X# {4 \, eAssume you want to run a regression of wage on age, work experience,education, gender, and a dummy for sectorofemployment (whether employed in the public sector). wage = function(age, workexperience, education, gender, sector) or, as your textbook will have it, wage = b1 + b2*age + b3*work experience+ b4*education + b5*gender + b6*sector The White’s test is usually used as a test for heteroskedasticity. In this test, a regression of the squares ofthe residuals is run on the variables suspected of causing theheteroskedasticity, their squares, and cross products. (residuals)2 = b0 + b1 educ + b2 work_ex+ b3 (educ)2 + b4 (work_ex)2 + b5(educ*work_ex)
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White’s Test · Calculate n*R2 à R2 = 0.037, n=2016 à Thus, n*R2 = .037*2016 = 74.6.
& V9 z9 B4 f @2 ]4 M- m8 I· Compare this value with c2 (n), i.e.with c2 (2016)
* W8 y" G% ?' Y' F- |4 o1 s7 x(c2 is the symbol for theChi-Square distribution) : O! b9 r9 n% Q4 \* i8 m% w
c2 (2016) = 124obtained from c2 table. (For 955 confidence) As n*R2 < c2 ,heteroskedasticity can not be confirmed.
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请参考:regression_explained_SPSS
regression_explained_SPSS.doc
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