I am estimating d in ARFIMA using fdGPH of fracdiff package in R. I am using both absolute return and squared return of exchange rate series.
My question is while estimating d using absolute return, i am finding negative value whereas with squared return, i am finding positive value.
I can't understand how to interpret the same?
Please help.
Thanks
I am facing problem in interpreting the negative value (for absolute return) and positive value (for squared return) of d in different bandwidth.