Research on judgment and decision making presents a confusing picture of human abilities. For example, much research has emphasized the dysfunctional aspects of judgmental heuristics, and yet, other findings suggest that these can be highly effective. A further line of research has modeled judgment as resulting from "as if" linear models. This paper illuminates the distinctions in these approaches by providing a common analytical framework based on the central theoretical premise that understanding human performance requires specifying how characteristics of the decision rules people use interact with the demands of the tasks they face. Our work synthesizes the analytical tools of "lens model" research with novel methodology developed to specify the effectiveness of heuristics in different environments and allows direct comparisons between the different approaches. We illustrate with both theoretical analyses and simulations. We further link our results to the empirical literature by a meta-analysis of lens model studies and estimate both human and heuristic performance in the same tasks. Our results highlight the trade-off between linear models and heuristics. Whereas the former are cognitively demanding, the latter are simple to use. However, they require knowledge -and thus "maps" -of when and which heuristic to employ.Keywords: Decision making; heuristics; linear models; lens model; judgmental biases.JEL classification: D81, M10.
3Two classes of models have dominated research on judgment and decision making over the last decades. In one, explicit recognition is given to the costs and limits of information processing and people are assumed to use simplifying heuristics -typically making use of only part of the information available (Kahneman, Slovic, & Tversky, 1982;Gigerenzer, Todd, & the ABC Research Group, 1999). In the other, it is assumed that people can integrate all the information at hand and that this is combined and weighted "as if" using an algebraic -typically linear -model (Anderson, 1981;Brehmer, 1994;Hammond, 1996).Research on these models has been conducted within different traditions with few attempts to unify the two approaches (however, see Hammond, 1990). Whereas such unification is not our goal, we recognize the validity of both approaches and seek to illuminate their complementarities. For example, recent research suggests that people can process information in distinctive ways (cf., Chaiken & Trope, 1999), variously described as "experiential" vs. "rational" (Epstein, 1994), "System 1" vs."System 2" (Stanovich & West, 1998), or "tacit" vs. "deliberate" (Hogarth, 2001).The former denote processes that are intuitive or heuristic whereas the latter are the outcomes of more deliberative processes. We do not propose a one-to-one correspondence between the dual process approach, on the one hand, and heuristic and algebraic models, on the other hand. However, the analogy emphasizes the advantages of seeking complementarities.The topic of heuristics has been central to research on judgm...