Qbank #86575 - Seasonally Adjusted Models following, adjusted

leadcfa

Which of the following is a seasonally adjusted model?
A) (Salest - Sales t-1)= b0 + b1 (Sales t-1 - Sales t-2) + b2 (Sales t-4 - Sales t-5) +

profil

It could be a monthly lagged model.

rohitdoshi

hahaha i felt the same way when I hit this problem.. I was wondering if anyone would point it out. I was like “couldn’t you argue B is a lagged model as well?”
i wonder if someone else could enlighten this.

dreampak

The question asked for an adjusted model, adjustments usually entail using a lagged term of some period to correct an observed effect, as seasonal in this case. B and C are simple lagged models. A adjusts t-1 and and 1-4 lags.