Heteroscedasticity Test Auto-Correlation Test

55 From the Figure 4.1 we can see that the probability of Jarque Bera of the consumer goods sector is bigger than α 0.269108 0.05. Thus, we failed to reject the Null Hypothesis and that means the residual of the model is normally distributed. From the Figure 4.2 we can see that the probability of Jarque Bera of the property and real estate sector is bigger than α 0.429778 0.05. Thus, we failed to reject the Null Hypothesis and that means the residual of the model is normally distributed.

D. Classical Assumption Test

In order to achieve the model that has BLUE characteristic, the writer needs to conduct the classical assumption test before doing the regression analysis. If in this test we find that the model is not resulting in BLUE characteristic we will use the remedial measurement accordingly.

1. Heteroscedasticity Test

One of the important assumptions of the classical linear regression model is that the variance of each disturbance, conditional on the chosen values of the explanatory variables, is somewhat constant. This is the assumption of homoscedasticity. To detect whether heteroscedasticity is present in the data, the writer will conduct a formal test using White Test method. The reason why we use White‟s General Heteroscedasticity Test is because it does not rely on the normality assumption and easy to implement. 56 After using the statistical software Eviews 5, the writer find the result of White Heteroscedasticity Test- No cross terms, as follows: White Heteroskedasticity Test: F-statistic 1.985143 Probability 0.084204 ObsR-squared 11.00974 Probability 0.088076 Table 4.2 Heteroscedasticity Test for Consumer Goods Sector Table 4.2 presents the result of the White Heteroscedasticity test on consumer goods sector using statistical software Eviews 5. The result of the test provides the proof that the data we are using is free from heteroscedastic problem homoscedastic. From the test above, we can see that the probability of ObsR- squared is bigger than our significant value 0.088076 0.05 and thus we can reject the null hypothesis. White Heteroskedasticity Test: F-statistic 0.538939 Probability 0.776195 ObsR-squared 3.450216 Probability 0.750581 Table 4.3 Heteroscedasticity Test for Property and Real Estate Sector 57 Table 4.3 presents the result of the White Heteroscedasticity test on property and real estate sector using statistical software Eviews 5. The result of the test provides the proof that the data we are using is free from heteroscedastic problem homoscedastic. From the test above, we can see that the probability of ObsR- squared is bigger than our significant value 0750581 0.05 and thus we can reject the null hypothesis.

2. Auto-Correlation Test

As in the case of heteroscedasticity, in the presence of autocorrelation the OLS estimators are still linear unbiased as well as consistent and asymptotically normally distributed, but they are no longer efficient i.e., minimum variance. To detect autocorrelation, the writer use The Breusch-Godfrey BG Test, which is also known as Lagrange-Multiplier LM Test in the application software EViews 5. The results are presented in tables below: Breusch-Godfrey Serial Correlation LM Test: F-statistic 0.150862 Probability 0.860328 ObsR-squared 0.333385 Probability 0.846460 Table 4.4 Auto-Correlation Test for Consumer Goods Sector Breusch-Godfrey Serial Correlation LM Test: F-statistic 0.587759 Probability 0.559086 ObsR-squared 1.278303 Probability 0.527740 Table 4.5 Auto-Correlation Test for Property and Real Estate Sector 58 From the Table 4.4 we find that the probability ObsR-squared from the data of consumer goods sector is bigger than sig. value α 0.846460 0.05, thus we can conclude that auto-correlation is not existed in our data. The same result happens in the property and real estate sector. As if presented in Table 4.5, the probability ObsR-squared is bigger than sig. value α 0.527740 0.05, thus we can reject the null hypothesis and conclude that there is no auto-correlation in our data.

3. Multi-Collinearity Test