Contrast effects in judgmental forecasting when assessing the implications of worst and best case scenarios

Two experiments investigated whether individuals’ forecasts of the demand for products and a stock market index assuming a best or worst-case scenario depend on whether they have seen a single scenario in isolation or whether they have also seen a second scenario presenting an opposing view of the future. Normatively, scenarios should be regarded as belonging to different plausible future worlds so that the judged implications of one scenario should not be affected when other scenarios are available. However, the results provided evidence of contrast effects in that the presentation of a second ‘opposite’ scenario led to more extreme forecasts consistent with the polarity of the original scenario. In addition, people were more confident about their forecasts based on a given scenario when two opposing scenarios were available. We examine the implications of our findings for the elicitation of point forecasts and judgmental prediction intervals and the biases that are often associated with them.

[1]  Sean Blair,et al.  Doing Well by Doing Good: The Benevolent Halo of Corporate Social Responsibility , 2015 .

[2]  Robert Fildes.  Scenarios: The Art of Strategic Conversation , 1998, J. Oper. Res. Soc..

[3]  S. Oskamp.  OVERCONFIDENCE IN CASE-STUDY JUDGMENTS. , 1965, Journal of consulting psychology.

[4]  Jennifer S. Trueblood,et al.  The Phantom Decoy Effect in Perceptual Decision Making , 2017 .

[5]  Nigel Harvey,et al.  Context-Sensitive Heuristics in Statistical Reasoning , 1993 .

[6]  Steve Begg,et al.  More-or-less elicitation (MOLE): reducing bias in range estimation and forecasting , 2018, EURO Journal on Decision Processes.

[7]  Kristine M. Kuhn,et al.  Confidence and Uncertainty in Judgmental Forecasting: Differential Effects of Scenario Presentation , 1996 .

[8]  S. Joslyn,et al.  The Advantages of Predictive Interval Forecasts for Non‐Expert Users and the Impact of Visualizations , 2013 .

[9]  C I HOVLAND,et al.  Assimilation and contrast effects of anchoring stimuli on judgments. , 1958, Journal of experimental psychology.

[10]  Steven P. Schnaars,et al.  The use of multiple scenarios in sales forecasting: An empirical test , 1987 .

[11]  Marcus O'Connor,et al.  Exploring judgemental forecasting , 1992 .

[12]  Paul Goodwin,et al.  Getting Real about Uncertainty , 2014 .

[13]  Nigel Harvey,et al.  Trend damping: Under-adjustment, experimental artifact, or adaptation to features of the natural environment? , 2013, Journal of experimental psychology. Learning, memory, and cognition.

[14]  A. Todorov,et al.  The illusion of knowledge: When more information reduces accuracy and increases confidence , 2007 .

[15]  Gabriele Pizzi,et al.  When Out-of-Stock Products DO Backfire: Managing Disclosure Time and Justification Wording , 2013 .

[16]  Thomas Oberlechner.  Psychology of Judgment and Decision-Making , 2006 .

[17]  P. Yelland.  Bayesian forecasting of parts demand , 2010 .

[18]  Mel W. Khaw,et al.  Normalization is a general neural mechanism for context-dependent decision making , 2013, Proceedings of the National Academy of Sciences.

[19]  E. Thorndike.  A constant error in psychological ratings. , 1920 .

[20]  George Cairns,et al.  Does the intuitive logics method – and its recent enhancements – produce “effective” scenarios? , 2013 .

[21]  M. Manis,et al.  Summarizing controversial messages: Retroactive effects due to subsequent information. , 1978 .

[22]  A. Tversky,et al.  Context-Dependence in Legal Decision Making , 1996, The Journal of Legal Studies.

[23]  Alireza Soltani,et al.  A Range-Normalization Model of Context-Dependent Choice: A New Model and Evidence , 2012, PLoS Comput. Biol..

[24]  Gill Ringland,et al.  Scenario Planning: Managing for the Future , 1998 .

[25]  A. Krishen,et al.  Fear advertisements: influencing consumers to make better health decisions , 2015 .

[26]  Florian Pappenberger,et al.  Do probabilistic forecasts lead to better decisions , 2012 .

[27]  An T. Oskarsson,et al.  What’s Next? Judging Sequences of Binary Events , 2008, Psychological bulletin.

[28]  Gordon D. A. Brown,et al.  Decision by sampling , 2006, Cognitive Psychology.

[29]  F. Strack,et al.  Explaining the Enigmatic Anchoring Effect: Mechanisms of Selective Accessibility , 1997 .

[30]  P. Winkielman,et al.  Assimilation and Contrast as a Function of Context-Target Similarity, Distinctness, and Dimensional Relevance , 1998 .

[31]  Nira Liberman,et al.  The effect of global versus local processing styles on assimilation versus contrast in social judgment. , 2008, Journal of personality and social psychology.

[32]  R. Fildes,et al.  Effective forecasting and judgmental adjustments: an empirical evaluation and strategies for improvement in supply-chain planning , 2009 .

[33]  Jacob Cohen.  Statistical Power Analysis for the Behavioral Sciences , 1969, The SAGE Encyclopedia of Research Design.

[34]  Ulrich Wilhelm Thonemann,et al.  Managers and Students as Newsvendors , 2012, Manag. Sci..

[35]  Gabriele Pizzi,et al.  The Impact of Phantom Decoys on Choices and Perceptions , 2013 .

[36]  P. Herr,et al.  On the consequences of priming: Assimilation and contrast effects , 1983 .

[37]  Frank Steiner,et al.  Leveraging the Sustainability Potential of Mass Customization through Product Service Systems in the Consumer Electronics Industry , 2015 .

[38]  Gordon D. A. Brown,et al.  Does the brain calculate value? , 2011, Trends in Cognitive Sciences.

[39]  Ed O'Donnell,et al.  The Halo Effect in Business Risk Audits: Can Strategic Risk Assessment Bias Auditor Judgment about Accounting Details? , 2005 .

[40]  William Remus,et al.  Graduate students as surrogates for managers in experiments on business decision making , 1986 .

[41]  A. Tversky,et al.  Choice in Context: Tradeoff Contrast and Extremeness Aversion , 1992 .

[42]  Timothy D. Wilson,et al.  The halo effect: Evidence for unconscious alteration of judgments. , 1977 .

[43]  Campbell R. Harvey,et al.  Managerial Miscalibration , 2010 .

[44]  Duane T. Wegener,et al.  Dimensional Range Overlap and Context Effects in Consumer Judgments , 2010 .

[45]  I. M. Gordon,et al.  Students as Surrogates for Managers: Evidence from a Replicated Experiment , 2018 .

[46]  Dilek Önkal,et al.  Scenarios as channels of forecast advice , 2013 .