Consider a random walk model with the following equation: Yt = Yt - 1 + et, where

Question:

Consider a random walk model with the following equation: Yt = Yt - 1 + et, where et is a random series with mean 0 and standard deviation 1. Specify a moving average model that is equivalent to this random walk model. In particular, what is the appropriate span in the equivalent moving average model? What is the smoothing effect of this span?