Hey Guys,
as you may be able to tell by my many posts tonight (Sorry about that !) im really trying to consolidate my time series understanding today.
Just two things i want to clear up
Firstly: when we pull out a factor of (1-B) this is equivalent of differencing once right? so i can say d=1? Equivalently (1-B^2) would be differencing twice etc? so how about if i can pull out (1-B)(1-0.5B) - ive seen solutions say this is differencing once, is it because of the coefficient of the second bracket, so that (1-0.5b) doesnt count as differencing? I hope that makes sense, essentially if i pulled out just (1-0.5B), would i be able to say ive differenced at all?
Secondly: is the error term the same as the white noise e_t term we see in most questions? they seem to be used interchangably in questions, but i could be wrong.
Thanks so much in advance.
as you may be able to tell by my many posts tonight (Sorry about that !) im really trying to consolidate my time series understanding today.
Just two things i want to clear up
Firstly: when we pull out a factor of (1-B) this is equivalent of differencing once right? so i can say d=1? Equivalently (1-B^2) would be differencing twice etc? so how about if i can pull out (1-B)(1-0.5B) - ive seen solutions say this is differencing once, is it because of the coefficient of the second bracket, so that (1-0.5b) doesnt count as differencing? I hope that makes sense, essentially if i pulled out just (1-0.5B), would i be able to say ive differenced at all?
Secondly: is the error term the same as the white noise e_t term we see in most questions? they seem to be used interchangably in questions, but i could be wrong.
Thanks so much in advance.