Fooled by facts: quantifying anchoring bias through a large-scale experiment

Through a large-scale online field experiment, we provide new empirical evidence for the presence of the anchoring bias in people’s judgement due to irrational reliance on a piece of information that they are initially given. The comparison of the anchoring stimuli and respective responses across different tasks reveals a positive, yet complex relationship between the anchors and the bias in participants’ predictions of the outcomes of events in the future. Participants in the treatment group were equally susceptible to the anchors regardless of their level of engagement, previous performance, or gender. Given the strong and ubiquitous influence of anchors quantified here, we should take great care to closely monitor and regulate the distribution of information online to facilitate less biased decision making.

Behavioral Factors Influencing Stock Investment Decision of Individuals

Purpose: The purpose of this study is to identify the behavioral factors influencing individual investors’ decisions and to analyze the relationship between these factors and investment decision performance. Design/Methodology/Approach: The tested variables were: Anchoring bias, Gambler’s Fallacy, Overconfidence bias, Availability and Representativeness bias from heuristics factor, Mental Accounting, Loss and Regret Aversion from prospect factor, and Market variables and Herding factors. The study employed exploratory and confirmatory factor analysis. In addition, structural equation modeling is applied for the testing of the hypotheses. Findings: Prospect behavioral factor is seen to have negative correlation to investment performance. Herding, Market variables and Heuristic (including overconfidence and anchoring bias) are found to have positive correlation to investment performance. Implications: To cope with intense competition among the competitors in Nepali stock market, this study provides strong evidence herding and heuristic approach that have positive indication to investment performance

Noise Increases Anchoring Effects

We introduce a theoretical framework distinguishing between anchoring effects, anchoring bias, and judgmental noise: Anchoring effects require anchoring bias, but noise modulates their size. We tested this framework by manipulating stimulus magnitudes. As magnitudes increase, psychophysical noise due to scalar variability widens the perceived range of plausible values for the stimulus. This increased noise, in turn, increases the influence of anchoring bias on judgments. In 11 preregistered experiments ( N = 3,552 adults), anchoring effects increased with stimulus magnitude for point estimates of familiar and novel stimuli (e.g., reservation prices for hotels and donuts, counts in dot arrays). Comparisons of relevant and irrelevant anchors showed that noise itself did not produce anchoring effects. Noise amplified anchoring bias. Our findings identify a stimulus feature predicting the size and replicability of anchoring effects—stimulus magnitude. More broadly, we show how to use psychophysical noise to test relationships between bias and noise in judgment under uncertainty.

Diagnostic delay of acute mitral regurgitation during the coronavirus disease 2019 pandemic: a case report

Background Diagnostic errors or delays can cause serious consequences for patient safety, especially in the emergency department. Anchoring bias is one of the major factors leading to diagnostic error. During the coronavirus disease 2019 (COVID-19) pandemic, the high probability of COVID-19 in febrile patients could be a major cause of anchoring bias leading to diagnostic error. In addition, certain evaluations such as auscultation are difficult to perform on a casual basis due to the increased risk of contact infection, which lead to inadequate assessment of the patients with valvular disease. Acute mitral regurgitation (MR) could be a fatal disease in the emergency department, especially if there is a diagnostic error or delay in diagnosis. It is often reported that diagnosis can be difficult even though there is no treatment other than emergent surgery. The diagnosis of acute MR has become more difficult because coronavirus disease 2019 (COVID-19) pandemic could affect our daily practice especially in febrile patients. We report a case of a diagnostic delay of a febrile patient because of anchoring bias during the COVID-19 pandemic. Case presentation A 45-year-old man presented to the emergency department complaining of acute dyspnea and fever. Based on vital signs and computed tomography of the chest, acute pneumonia due to COVID-19 was suspected. Auscultation was avoided because of facility rule based on concern of contact infection. After admission to the intensive care unit, Doppler echocardiography revealed acute mitral regurgitation, and transesophageal echocardiography revealed mitral valve tendon rupture. After confirming the negative result for the polymerase chain reaction of severe acute respiratory syndrome coronavirus 2, mitral valvuloplasty was performed on the third day after admission. The patient was discharged 14 days after admission without complications. Conclusions In COVID-19 pandemic, anchoring bias suspecting COVID-19 among febrile patients becomes a strong heuristic factor. A thorough history and physical examination is still important in febrile patients presenting with dyspnea to ensure the correct diagnosis of acute mitral regurgitation.

Facial Pyoderma Gangrenosum: Overcoming Anchoring Bias

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Why Retractions of Numerical Misinformation Fail: The Anchoring Effect of Inaccurate Numbers in the News

Numbers can convey critical information about political issues, yet statistics are sometimes cited incorrectly by political actors. Drawing on real-world examples of numerical misinformation, the current study provides a first test of the anchoring bias in the context of news consumption. Anchoring describes how evidently wrong and even irrelevant numbers might change people’s judgments. Results of a survey experiment with a sample of N = 413 citizens indicate that even when individuals see a retraction and distrust the presented misinformation, they stay biased toward the initially seen inaccurate number.