The Null Hypothesis - H0: γ_{1} = γ_{2 = ... = }0 i.e. there is no heteroscedasticity in the model
The Alternative Hypothesis - H1: at least one of the γ_{i}'s are not equal to zero i.e. the squared residuals are related to one of the independent variables.
Reject H0 if nR^{2} >
Regression Analysis: sqresi versus totexp, age, ...
* sqnk is highly correlated with other X variables
* sqnk has been removed from the equation.
The regression equation is
sqresi = 0.00086 - 0.000117 totexp + 0.000765 age + 0.00007 nk
+ 0.000000 sqtotexp - 0.000009 sqage + 0.000000 totexpage
+ 0.000026 totexpnk - 0.000077 agenk
Predictor Coef SE Coef T P VIF
Constant 0.000857 0.007288 0.12 0.906
totexp -0.00011676 0.00004906 -2.38 0.017 49.148
age 0.0007649 0.0003256 2.35 0.019 73.466
nk 0.000072 0.002941 0.02 0.980 24.250
sqtotexp 0.00000019 0.00000010 2.00 0.045 13.958
sqage -0.00000879 0.00000394 -2.23 0.026 62.515
totexpage 0.00000021 0.00000097 0.21 0.831 37.830
totexpnk 0.00002598 0.00001464 1.77 0.076 18.920
agenk -0.00007694 0.00007905 -0.97 0.331 32.566
S = 0.0112807 R-Sq = 1.2% R-Sq(adj) = 0.6%
Analysis of Variance
Source DF SS MS F P
Regression 8 0.0022313 0.0002789 2.19 0.026
Residual Error 1493 0.1899897 0.0001273
Lack of Fit 639 0.0804237 0.0001259 0.98 0.601
Pure Error 854 0.1095659 0.0001283
Total 1501 0.1922209
332 rows with no replicates
Source DF Seq SS
totexp 1 0.0006642
age 1 0.0000000
nk 1 0.0000026
sqtotexp 1 0.0005240
sqage 1 0.0005895
totexpage 1 0.0000013
totexpnk 1 0.0003292
agenk 1 0.0001206
MTB > let k4=1502*0.012
MTB > print k4
Data Display
K4 18.0240
Inverse Cumulative Distribution Function
Chi-Square with 8 DF
P( X <= x ) x
0.95 15.5073
Since nrsq = (1502*0.012) 18.024 > 15.5073 = , there is sufficient evidence to reject H0 which suggests that there is heteroscedasticity in the model from White's general heteroscedasticity test at the 5% significance level. Both Breusch Pagan test and White's general heteroscedasticity test seem to indicate that totexp is the culprit as the T value is significant and the P-value is 0.000.