Information mispurchase in judgment tasks: A task-driven causal mechanism

Numerous studies of predecisional information purchase indicate that humans are often seriously suboptimal in balancing the costs and benefits of the information they purchase. Underpurchase is reported in some tasks, over-purchase in others, but no convincing account has been offered of the mechanisms producing these patterns of error. The present paper attempts such an account. We first show by computer simulation that simple hill-climbing algorithms reliably reproduce patterns of over-and underpurchase found in earlier studies, and identify the task characteristics that drive this result. We then specify a novel task that should, by this account, yield a new pattern of purchase error and demonstrate that both simulated and real subjects do, in fact, show such error patterns. Implications are drawn both for research strategy in the area and for practical application.