# Specifying the bandwidth parameter for Local Whittle estimation

In every Local Whittle function I have seen I have to set bandwith parameter usually denoted m such that

m = floor(1+T^delta).

I am interested in the delta, how do I choose what value to put in the delta? Is there a way to estimate it from the data?

From what I have seen so far people usually use .65 or .7, what is the reason for that?