Contents
Is breusch-Pagan test reliable?
Moreover, in comparison with the wild bootstrap “version” of the original Breusch–Pagan test (Godfrey and Yamagata, 2011) our experiments indicate that the corresponding version of the heteroskedasticity-robust Breusch–Pagan test appears reliable.
What is the null hypothesis of breusch-Pagan test?
The null hypothesis for this test is that the error variances are all equal. The alternate hypothesis is that the error variances are not equal. More specifically, as Y increases, the variances increase (or decrease).
What does a violation of homoscedasticity mean?
Violation of the homoscedasticity assumption results in heteroscedasticity when values of the dependent variable seem to increase or decrease as a function of the independent variables. Typically, homoscedasticity violations occur when one or more of the variables under investigation are not normally distributed.
What is homoscedasticity formula?
3.02. In matrix notation, homoscedasticity is expressed as var(ɛ) = Iσ2 and heteroscedasticity as var(ɛ) = diag[σ12, σ22,…, σI2], where we again assumed that the errors are uncorrelated (so the off-diagonal terms of the variance–covariance matrix are zero).
Is the Breusch Pagan test heteroscedastic or homoscedastic?
However, a Breusch-Pagan test shows a significance of 0.000 and thus rejects the null hypothesis of homoscedasticity. According to the test, it is heteroscedastic. Should I still assume homoscedasticity and therefore interpret the results using robust standard errors and the HC3 method?
How to perform a Breusch Pagan test in R-statology?
A Breusch-Pagan Test is used to determine if heteroscedasticity is present in a regression analysis. This tutorial explains how to perform a Breusch-Pagan Test in R. Example: Breusch-Pagan Test in R
Which is the correct result for the Breusch-Pagan test?
The Breusch–Pagan test tells me that there is heteroskedasticity, while the White’s test tells me the opposite. Which result should I use? The Breusch-Pagan test only checks for the linear form of heteroskedasticity i.e. it models the error variance as σ i 2 = σ 2 h ( z i ′ α) where z i is a vector of your independent variables.
Is the scatter plot typical for homoscedasticity?
The scatter plot with standardized residual against studentized value is typical for homoscedasticity of residuals which is a triangular shape. However, a Breusch-Pagan test shows a significance of 0.000 and thus rejects the null hypothesis of homoscedasticity. According to the test, it is heteroscedastic.