The input bias: The misuse of input information in judgments of outcomes

In this paper we identify an input bias, the systematic misuse of input information in judgments of outcome quality. In many settings irrelevant input measures, such as the amount of time an employee spends in the office, influence outcome assessments, such as performance reviews. Across four studies we find that input values subtly, but significantly distort judgments of outcome quality. Irrelevant input information predictably influences outcome assessments even when people recognize that input measures should not matter and believe that input information did not matter. We examine the mechanics of the input bias, and suggest that because input measures are often easy to manipulate or misrepresent, the input bias is likely to have broad implications for managerial judgment and decision making. (C) 2003 Elsevier Science (USA). All rights reserved.