1. 用图表检验Analyze -> regression -> Linear-> Plots
/ C( h0 l5 g# y1 yScatter plot of the standardised residuals on the standardised predicted values (ZRESID as the Y variable, and ZPRED as the X variable
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1 M5 X5 u; E, l8 H: ?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。
- I8 u9 J8 L9 w; e- K% x* ~) W2. 用统计检验
9 a) c$ O+ E$ R3 g; XHeteroscedasticity——Testing and Correcting in SPSS.pdf
Gwilym Pryce March 2002.doc
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Levene’s Test
! V* D" S! W: E8 qGoldfeld-Quandt Test- g9 T% }2 p' }7 q# g V0 B/ q* f
Breusch-Pagan Test
: k2 X: U- o6 ?. H1 _9 M1 |2 K% CWhite‘s Test (比较常用来检验异方差)
: Y* Z' C. O* J- cAssume 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) - |0 v2 \6 ]- n1 F5 B
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White’s Test · Calculate n*R2 à R2 = 0.037, n=2016 à Thus, n*R2 = .037*2016 = 74.6.
. }, e7 G. U) }0 y. c( x$ f4 {· Compare this value with c2 (n), i.e.with c2 (2016) 3 |5 D3 Z6 h7 L0 D4 M" f7 y
(c2 is the symbol for theChi-Square distribution) 1 W5 ^% Q, `7 g' O7 r
c2 (2016) = 124obtained from c2 table. (For 955 confidence) As n*R2 < c2 ,heteroskedasticity can not be confirmed. 5 `/ p7 \9 F& L/ I- C, S
, p$ Z0 g! ?) C请参考:regression_explained_SPSS
regression_explained_SPSS.doc
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