Forecasting is necessary for organizations to prepare for the future for effective operations and this forecasting process largely relies on human judgment. It is therefore, important to examine ways to improve judgmental forecasting accuracy. This dissertation consists of two essays focusing on ways to improve judgmental forecasting performance. In the first essay, “Individual and Group Differences in Advice Taking Behavior: Perspectives in Judgmental Forecasting,” I examine advice taking behavior when individuals and groups make judgmental forecasts given external forecast advice. Using a controlled laboratory experiment, I investigate the differences between individuals and groups in the degree of advice taking and the ability to discern advice quality. Participants in an individual condition make decisions individually without any interactions with others whereas participants in a group condition interactively discuss with other two participants and agree on single decisions. I examine two studies regarding the distribution of advice quality; in Study 1, participants are randomly assigned to one of the two advice quality conditions where the same quality advice, either unreasonable or reasonable forecast advice, is given, and in Study 2, participants receive variable advice quality. In both studies, I find that groups are less receptive to advice than individuals and this relationship is mediated by confidence level; groups feel more confident than individuals, which decreases reliance upon advice. We also find that groups, who feel more confident, are able to discriminate the quality of advice better than individuals. In Study 2, I explicitly measure the disagreement level in a group and find that higher disagreement level in a group leads to lower confidence level, which then increases group’s reliance upon advice.
In the second essay, “The Effect of Relative Performance Feedback on Judgmental Forecasting Accuracy,” using a controlled laboratory experiment, I test the effect of providing relative performance feedback on judgmental forecasting performance. I show that relative performance feedback that provides rank information compared to other competing participants improves forecasting accuracy compared to the case without such feedback. We also find that the effect of relative performance feedback depends on the content of the feedback information as well as whether it is tied to additional financial reward. Relative performance feedback becomes more effective when subjects are informed that they rank behind other competing participants, compared to when subjects are informed that they rank above other competing participants. This finding is consistent with loss aversion: Low-ranked individuals view their performance as a loss and work harder to avoid this. By contrast, leading participants tend to slack off. Lastly, I find that the addition of monetary reward paid to top performing individuals reduces the effect of relative performance feedback, particularly for bottom performing individuals.
예측은 기업이 효율적으로 운영하기 위하여 필요하며, 이 과정에서 사람의 주관은 필수적이다. 따라서, 주관적 예측 성과를 향상시키는 방법을 도출하는 것이 중요하다. 본 학위 논문은 이러한 주관적 예측 성과를 향상시키는 방법에 중점을 둔 두 개의 논문으로 구성되어있다. 첫 번째 논문은 예측 조언이 제공될 때의 개인과 그룹간의 예측 행태를 비교하였다. 특히, 조언 수용 정도와 조언의 질의 구분하는 정도 측면에서 비교하였다. 그룹이 개인보다 조언에 대한 수용력이 낮으며, 이것은 그룹이 개인보다 자신이 만든 예측치에 대한 확신이 높았기 때문이다. 또한, 그룹은 조언의 질을 잘 구분하여 받아드린 반면에, 개인은 조언의 질과 상관없이 조언에 대한 의존도가 높았다. 두 번째 논문은 상대적 성과 피드백 제공이 예측 성과에 미치는 영향을 살펴보았다. 상대적 순위 정보를 제공하는 것이 그러한 피드백이 없는 경우에 비해 예측 정확도를 향상시켰다. 특히, 순위가 높다고 알리는 것보다 낮다고 알리는 경우가 더 효과적이었으며, 이것은 손실회피성향으로 설명될 수 있다. 또한 성과 피드백의 효과는 금전적 보상의 유무에 따라 증가되고 감소되었다. 금전적 보상은 성과가 상대적으로 좋지 않은 사람의 경우 비효과적이었다.
