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A Demonstration of the Anchoring Effect
Richard
E. Kopelman and Anne L. Davis
Department of Management
Zicklin
School of Business
Baruch
College
One
Bernard Baruch Way, Box B 9-237
New
York, NY 10010-5585
Richard_Kopelman@baruch.cuny.edu
646-312-3629
To
guess is inexpensive; to guess wrong can be very costly.
Ancient Chinese
proverb
In this teaching
brief, we describe a technique
for
demonstrating how cognitive heuristics subtly (and sometimes
perniciously) affect decision-making. More specifically, we describe a
method for illustrating the anchoring effect. Awareness of this effect
is, logically, the first step toward obviating and/or removing the
potential biases that may result from basing decisions on
unreliable/irrelevant information. [1]
Cognitive
heuristics are mental mechanisms used to cope with the uncertainty and
complexity of the decision-making environment (Bazerman, 2002). By
reducing the amount of information taken into consideration, heuristics
simplify and speed up the decision-making process (Schwenk, 1986). But
the heuristics employed can have negative consequences, resulting in
sub-optimal decisions.
Anchoring is one such heuristic, where managers make a decision based on
an initial parameter or parameters (Tversky & Kahneman, 1974). The
initial value(s) may be drawn from memory or experience, or may be
supplied by others. When based on irrelevant or no longer pertinent
information, faulty decisions are likely to result. When making
forecasts, people often use the past as the starting point. While the
past may be relevant, the environment may offer other pertinent clues to
the future. Illuminating potential anchoring biases may enable
decision-makers to consider what information they are considering.
Bazerman
(2002) discussed a model for improving decision-making that builds on
Lewin’s (1947) framework of unfreezing, change, and refreezing. Making
people aware of a potential anchoring bias may allow them to unfreeze
their decision-making process. If anchoring is successfully
demonstrated, the decision maker is likely—at least in future
decisions—to consider the possibility that s/he has permitted a
potentially irrelevant or incorrect piece of information to anchor or
bias the decision. This revelation may thereby result in a change in
his/her decision-making behavior. If that change proves to be
successful, refreezing will likely occur as the decision-maker
incorporates knowledge of anchoring into future decisions.
The
teaching of cognitive heuristics is particularly relevant to courses in
organizational behavior and managerial decision-making. Not only can
this knowledge be useful to future managers in improving their own
decision-making abilities, but it can also illuminate why bosses and
subordinates make the decisions they make. But simply telling (i.e.,
lecturing) students about cognitive heuristics is not likely to be
enough. An active demonstration of the anchoring bias that personally
involves the students is more likely to unfreeze the decision-making
process.
Bonwell and Eison (1991, p.2) define active learning as “anything that
involves students in doing things and thinking about the things they are
doing.” Sivan, Leung, Woon, and Kember (2000) demonstrated that active
learning promotes the development of critical thinking and problem
solving, two important skills for decision-makers at all levels.
Oslund,
Rubin, and Kolb (2000), in the context of higher organizational
behavior, and Silberman (1998) in connection with training, recommend
combining abstract, conceptual learning with active problem solving in
the teaching of organizational psychology. Making concepts pertinent to
students’ future employment by giving concrete illustrations enhances
the relevance of the course content. Our demonstration incorporates an
active learning approach along with a conceptual explanation of the
anchoring effect.
THE
EXERCISE
The
exercise is conducted in the form of a problem set completed in class.
All participants are given a scenario in which they are asked to make a
judgment. The scenario includes information that is intended to be
irrelevant to the judgment at hand, but which may serve as an anchor
nonetheless. On a random basis, one-half of the students receive the
low anchor scenario; the other one-half receive the high anchor
scenario. Students are not informed about the existence of two
scenarios. Upon completing the problem set, students are directed to
transfer their answers to the last page (the answer page), and to tear
it off and pass it along to the teaching assistant (or to volunteer
student scorers) for scoring. The two versions of the problem appear
below:
Here is the low anchor version, labeled
Problem 2:
A newly hired engineer for a medical laser
firm in San Diego had four years of experience in excimer lasers and
excellent qualifications. When asked to estimate the starting salary
for this employee, my administrative assistant (knowing very little
about the profession or the industry) guessed an annual salary—excluding
benefits—of $45,000. What is your estimate?
Here is the high anchor
version, labeled Problem Two:
A newly hired engineer
for a medical laser firm in San Diego had four years of experience in
excimer lasers and excellent qualifications. When asked to estimate the
starting salary for this employee, my administrative assistant (knowing
very little about the profession or the industry) guessed an annual
salary—excluding benefits—of $145,000. What is your estimate?
The job of
excimer laser engineer was selected because it was reasoned that very
few students would have accurate information as to salary. The location
of San Diego was selected so that all participants used the same
location as a basis for their estimate. The executive assistant’s
opinion is the only different piece of information received between the
two groups of students. Note that both versions stipulate that the
executive assistant does not have any knowledge on the salary of the
excimer laser engineer. (Results would likely have been more powerful
without this disclaimer.)
During
the 15-minute period while the professor gives a brief lecture on
various forms of cognitive heuristics and their effects on
decision-making, the mean scores are calculated for the two groups.
(The answer page allows the identification of the scenario condition:
the label “Problem 2” is used in the low anchor group; the label
“Problem Two” denotes the high anchor condition.) Typically, the
lecture includes the biases emanating from the representativeness
heuristic (e.g., regression to the mean, the conjunction fallacy), the
availability heuristic (e.g., ease of recall, vividness), and the
anchoring/adjustment heuristic (e.g., overconfidence, anchoring effect)
(Bazerman, 2002). When it comes time to debrief the exercise (but prior
to telling them about the fact that there are two different versions),
it is instructive to ask a small group of students to indicate their
answers, and how they arrived at them. When asked, students will say
that they did not take the secretary’s estimate into account when
forming their own judgment. Next, when discussing the potential bias of
cognitive anchors, the instructor reports the means in the two
conditions. Students subsequently are surprised by the existence of two
conditions, and look at each other’s problem sheets to verify the
existence of differing anchors.
RESULTS
The above
technique has been used in thirteen separate trials over a period of 10
years. Participants have been both graduate and undergraduate students
attending public and private institutions. In all trials, the mean for
those given the high anchor point has exceeded the mean for those given
the low anchor point. Mean scores across the 13 administrations (unweighted)
were $99,790 and $68,860 in the high and low anchor conditions,
respectively, t = 7.45 (p < .001). Put differently, the
average estimate in the high anchor condition is approximately 45%
greater than the average estimate in the low anchor condition!
Remarkably, this demonstration has never failed to elicit a sizable
anchor effect, which is all the more compelling in light of the fact
that many students informally say that they discounted the anchor (i.e.,
the secretary’s estimate) when forming their own judgment. Students are
surprised and impressed by the magnitude of the effect demonstrated by
this exercise and it piques their interest in the effects of other
sources of decision bias. Presentation of the results to date seemingly
eliminates skepticism that the present results are an anomaly.
DISCUSSION
Clearly there
has been a reliable short-term effect. A long-term evaluation assessing
the effectiveness of this demonstration should also be performed,
possibly comparing students who have participated in the anchoring
demonstration to those who have merely read or heard about the anchoring
effect.
Some
educators are reluctant to use active learning exercises in general:
classroom time is limited; outcomes are uncertain. This exercise can be
counted on to succeed—at least until “word of mouth” communication among
students diminishes the pool of students unaware of the anchoring
effect.
Finally, it is worth noting that the present problem set protocol could
be expanded to demonstrate other decision biases. For example, a
scenario might be developed where a building initially purchased for
$400,000 (by one-half the class), or $100,000 (by the other half), is
now worth $200,000. The fact set could permit a tax-free swap into a
superior building worth $200,000 or the present building might be held
until it is worth $400,000, and swapped for an even better building.
This situation would illustrate how the consideration of sunk costs may
confound the decision process.
REFERENCES
Bazerman, M.H. (2002). Judgment in Managerial
Decision Making, 5th ed. New York:
John Wiley & Sons.
Bonwell, C.C. & Eison, J.A. (1991). Active
learning: Creating excitement in the classroom.
ASHE-ERIC Higher Education Report No. 1.
The George Washington University, School
of Education and Human Development,
Washington, DC.
Lewin, K. (1947). Frontiers in group dynamics:
Concept, method, and reality in social science;
social equilibria and social change. Human
Relations, 1, 5-41.
Oslund, J., Rubin, I.M., & Kolb, D. A. (2000). Organizational
behavior: An experiential approach. Englewood Cliffs, NJ:
Prentice-Hall.
Roxburgh, C. (2003). Hidden flaws in strategy.
McKinsey Quarterly, Spring 2003(2), 26-40.
Schwenk, C.R. (1986). Information, cognitive
biases, and commitment to a course of action.
Academy of Management Review, 11,
298-310.
Silberman, M. (1998). Active Learning, 2nd
Ed. San Francisco: Jossey-Bass/Pfeifer.
Sivan, A., Leung, R.W., Woon, C., & Kember, K.
(2000). An implementation of active learning
and its effect on the quality of student
learning. Innovations in Education and Training
International, 37(4), 381-389.
Tversky, A. & Kahneman, D. (1974). Judgment under
uncertainty: Heuristics and Biases.
Science, 185, 1124-1131.
_____________________
[1] The authors thank Professor Joel Brockner,
Columbia Business School, and two anonymous reviewers for their helpful
comments.
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