Biased information processing in the escalation paradigm: information search and information evaluation as potential mediators of escalating commitment.

Escalation of commitment denotes decision makers' increased reinvestment of resources in a losing course of action. Despite the relevance of this topic, little is known about how information is processed in escalation situations, that is, whether decision makers who receive negative outcome feedback on their initial decision search for and/or process information biasedly and whether these biases contribute to escalating commitment. Contrary to a widely cited study by E. J. Conlon and J. M. Parks (1987), in 3 experiments, the authors found that biases do not occur on the level of information search. Neither in a direct replication and extension of the original study with largely increased test power (Experiment 1) nor under methodologically improved conditions (Experiments 2 and 3) did decision makers responsible for failure differ from nonresponsible decision makers with regards to information search, and no selective search for information supporting the initial decision or voting for further reinvestment was observed. However, Experiments 3 and 4 show that the evaluation of the previously sought information is biased among participants who were responsible for initiating the course of action. Mediation analyses show that this evaluation bias in favor of reinvestment partially mediated the responsibility effect on escalation of commitment.