Adrian Trapletti wrote:




Ok I made Jarque-Bera test to the residuals (merv.reg$residual)


library(tseries)
jarque.bera.test(merv.reg$residual)
X-squared = 1772.369, df = 2, p-value = < 2.2e-16
And I reject the null hypotesis (H0: merv.reg$residual are normally
distributed)

So I know that:
1 - merv.reg$residual aren't independently distributed (Box-Ljung test)
2 - merv.reg$residual aren't indentically distributed (Breusch-Pagan test)
3 - merv.reg$residual aren't normally distributed (Jarque-Bera test)


My questions is:
It is possible merv.reg$residual be uncorrelated ?
cov[residual_t, residual_(t+k)] = 0 ?
Even when residuals are not independent distributed !




Yes. E.g., in an ARCH(1) process, cov[y_t, y_(t+k) ] = 0 (k \neq 0), but cov[(y_t)2, (y_(t+k))2 ] \neq 0,



The last equation should be autocov[y_t, y_(t+k)] \neq 0 or equivalently cov[(y_t)2, (y_(t+k))2 ] \neq (E[(y_t)2])2

I don't know what I was thinking here, but it is a complete nonsense. My first remark (The line starting with "Yes.") was just correct.


best
Adrian

______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

Reply via email to