The decision impact of opportunity costs is of interest to accountants, economists, and behavioral scientists. From an economic point of view these costs are generally considered relevant, and explicitly reporting them for decision making could improve the quality of future decisions. Much of the discussion in the literature concerns the definition or normative use of these costs (Burch and Henry [1970] and McRae [1970]). Recently, however, attention has turned to the descriptive aspects of the use of opportunity costs. Do managers, consumers, and other decision makers use opportunity costs in the way prescribed by standard economic theory? Thaler [1981], for instance, cites the underweighting of opportunity costs as an explanatory variable of consumer choice. Three recent studies in accounting (Becker, Ronen, and Sorter [1974] and Neumann and Friedman [1978; 1980]) investigated the use of opportunity costs in decision making, and although the evidence is somewhat mixed, decision makers seemed to ignore or underweight those costs. If decision makers do ignore or underweight opportunity cost relative to a normative standard, one interesting question is why? While there may be many reasons these costs are underweighted, only two were selected for my study. The main reason considered was the explicit availability of opportunity cost information. Since opportunity cost information is oftentimes unavailable or not collected, decision makers may have difficulties incorporating it when it is available (e.g., see Swieringa,