Reactions to decisions with uncertain consequences: reliance on perceived fairness versus predicted outcomes depends on knowledge.

Many decisions made by authorities pose uncertain consequences for the individuals affected by them, yet people must determine the extent to which they will support the change. Integrating the social justice and behavioral decision theory literatures, the article argues that individuals determine their support for proposed initiatives by assessing how knowledgeable they feel and using 2 main sources of information more or less heavily: their prediction of how the outcome of the initiative is likely to affect them or the perceived fairness of the decision maker. Three studies (2 experiments, 1 longitudinal field survey) assessing support for proposed public policies reveal that when individuals feel very knowledgeable they rely more on their prediction of how the outcome will affect them, whereas when they feel less knowledgeable they rely more on an overall impression of procedural fairness. The theoretical account and findings shed interdisciplinary insights into how people use process and outcome cues in reacting to decisions under uncertainty and ambiguity.