10 Working (1960)’s analysis shows that if consumers with time separable preferences make purchase decisions more often than consumption data are observed, time aggregation generates an MA(1) process in observed consumption growth even when preferences are otherwise standard as in Hall (1978). In a simple habit formation or sticky information model of the type presented in this paper, time aggregation generates an MA(2) process in consumption growth (Muellbauer (1988), Sommer (2007)), but the MA(2) coefficient is generally small.