Abstract: | ABSTRACT In this paper we extend the contextual theory of demand to consider rational consumer behavior when the household must deal with some random fluctuation in the prices it faces. Prices at stores reflect “advertised specials,” which are potential cost reductions random across goods, and random in-store price changes, which can only be observed by visiting the store. Our theory of rational behavior includes: (1) calculation by the household of an ex ante plan for its planning period; (2) modification to take account of advertised specials; and (3) rational search behavior to take advantage of random fluctuations observable only on a given day. This theory utilizes an active cash balance as a buffer against random variations from planned daily expenditures, and reformulations of trip circuits to account for patterns of cost-minimizing search. |