A positive flow of intended inventory investment occurs when a firm expects that sales will be high enough that the current level of inventories on hand may be insufficient—perhaps because in the presence of very short-term fluctuations in the timing of customer purchases, there is a risk of temporarily being unable to supply the product when a customer demands it. To avoid that prospect, the firm deliberately builds up its inventories—that is, engages in positive intended inventory investment by deliberately producing more than it expects to sell. Economists view this positive intended inventory investment as a form of spending—in effect, the firm is buying inventories from itself.