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ERIC Number: ED537075
Record Type: Non-Journal
Publication Date: 2011
Pages: 195
Abstractor: As Provided
Reference Count: 0
ISBN: ISBN-978-1-2671-0288-1
An Investigation into Appraisal Bias: The Role of Decision Support Tools in Debiasing Valuation Judgments
Tidwell, Owen Alan
ProQuest LLC, Ph.D. Dissertation, Georgia State University
Given the nature of the valuation task environment appraisers are often made aware of previous value opinions rendered by appraisers, commonly in the form of an historic appraisal. And, because an appraisal task involves the rendering of market value, a hypothetical, unobservable construct based on probabilities, direct feedback against this objective is typically not possible. Therefore, alternate signals derived from the task environment such as confirmation of previous appraised values may be employed, thereby potentially altering the appraiser's perception of the valuation objective leading to divergence from the normative model. Indeed, Diaz and Hansz (1997) and Diaz and Hansz (2001) illustrate appraiser susceptibility of this reference point in the real estate appraisal domain. The use of this heuristic is typically aimed at reducing cognitive search costs, however, the consideration of a previous value opinion is, of course, in contradiction to the appraisal normative model. However, the real estate behavioral literature suggests commercial appraisers have been susceptible to anonymous value opinions of experts, a clear deviation from the normative model, often times resulting in biased valuation judgments. Recently, research programs have examined potential "debiasing" techniques to moderate or eliminate systematic biases which under certain conditions result from the use of heuristics. One approach to debiasing is through the use of decision support tools and informational displays. This approach is coined the "technologist" approach because it relies on technology external to the decision maker (Larrick, 2004). In recognizing that attention and processing ability are scarce resources of a decision maker, and that acquiring and processing information can be costly, the use of technology in the form of a decision support tool has the ability to reduce search and processing cost (Payne, Bettman, and Schkade, 1999). In the context of commercial real estate, the emergence of CoStar and other providers of real estate information and analytics now provide decision support tools for real estate professionals including appraisers. Conlisk (1996) suggests that a reduction in informational search and processing costs may lessen the decision makers' reliance on cognitive simplification mechanisms. Thus, technologist contend that through the use of external decision support tools, systematic bias in decision making can be subdued or eliminated and the decision making process can approach the normative standard. The extent to which decision support tools reduce search cost is positively related to their effectiveness. Decision maker's strategies are adaptive and generally result in a strategy which maximizes accuracy while minimizing search cost (Einhorn and Hogarth, 1981; Payne 1982; Johnson and Payne, 1985). The use of external decision support tools can successfully eliminate biases if they can be implemented with little cognitive effort. The use of CoStar as a decision support tool in the commercial valuation context is expected to reduce the costs associated with the application of the normative appraisal model, resulting in a reduction in cognitive effort; and therefore should be utilized as a potential debiasing tool. The technologist view suggests that commercial appraisers' utilizing external decision support tools which contain readily available standardized data will result in appraisers having increased confidence in their valuation estimates due to a reduction in market uncertainties. This increase in confidence, results in appraisers who are less susceptible to non-sanctioned heuristic influence. Indeed, Levy and Schuck (1999) contend that access to comprehensive in-depth market information would increase appraisers' confidence in their initial value judgments and lessen the amount of potential heuristic influence. Additionally, Molloy and Schwenk (1995) find the use of information technology that allows for efficient scanning of data increases decision makers' confidence in their decisions. This research will be the first to focus on decision support tools as a technique to eliminate systematic biases in the appraisal process. The study focuses on the value opinion of an anonymous expert as a source of potential bias, because the value opinion of an anonymous expert is a common non-sanctioned source of influence representing a clear departure in the normative appraisal process. Also expert value opinions exerted the least amount of influence on appraisers, although still statistically significant, compared to other tested reference points (Diaz and Hansz, 2001). Therefore, the efficacy of decision support tools in debiasing valuation judgments is likely to be highest for groups receiving expert value opinions as a treatment. To operationalize the research hypotheses a two-factor randomized experiment to investigate the stated research hypotheses was conducted. One of the factors of interest is the impact of a previous value judgment of an anonymous expert on the appraisal process. The reference point (anonymous expert's opinion of value) was administered to two broad groups (CoStar and NonCostar groups) of subjects comprising the second factor. (Abstract shortened by UMI.) [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page:]
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Publication Type: Dissertations/Theses - Doctoral Dissertations
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A