What‘s the distinction between hp filter and moving average method?

[Zhang Hui]

Hi, I have a question. Is there a forward-looking moving average method?

y_trend =( y_{t+1} +y_{t} +y_{t-1})/3

And I also want to know more about the distinction between 'tsfilter hp' and 'hprescott' if anyone knows it. It seems that these two packages are similar.
Thanks a lot.

[Nick Cox]

You naturally can average based on any combination of lagging, current and leading values; the only questions are when you run out of any of those to do the calculations and what any average means for your purpose.

hprescott and tsfilter hp are just different implementations of the Hodrick-Prescott method. The first is (was?) community-contributed and the second officlal. My understanding is that the method is in essence a spline method although it often appears to be explained in highly idiosyncratic terms.

[Zhang Hui]

Thanks for Prof. Nick's great advice. I will try it.