I 13 7 3 1 1 1970 new classicals 1 1961 D S P Pe D = a Ä bP (1) S = c + dPe + u; E[u] = 0 (2) u D = S (3) (1) (2) PÉ = a Ä c b Ä d b Pe Ä u b (4) 1 2000 127 I 13 7 3 2 u E[u] = 0 E[PÉ ] = a Ä c b Ä d b Pe (5) Pe = E[PÉ ] (6) (5) E[PÉ ] (6) Pe Pe = a Ä c b + d (7) futg MA I 13 7 3 3 The term `rational expectations,' as Muth used it, refers to a consistency axiom for economic models, so it can be gi