3. Suppose that utility ( w) from consumption ( c) in any period t is given by u = In(c). (i) Using the consumption Euler equation, explain why Hall's random walk result for con- sumption fails. (ii) How can the properties of logarithmic utility be used to explain the excess smoothness of consumption? (iii) Briefly, what other factors may be important in explaining the evidence for excess sensitivity and excess smoothness in consumption