The decoy option: how the shortlist can change the choice
A committee rarely compares offers in isolation: it evaluates them within a shortlist prepared beforehand. The managerial question is specific: can adding a proposal that is clearly inferior to one offer favour that offer, even though its characteristics remain unchanged?
What the literature establishes
Joel Huber, John W. Payne and Christopher Puto (1982, Journal of Consumer Research) demonstrated experimentally that adding an asymmetrically dominated option can increase the probability of choosing the option that dominates it. On the attributes presented, the new proposal is inferior to one of the original options, but is not clearly dominated by the other. It is therefore more than an additional offer: it can shift preferences between offers already available.
A comparison that provides a reason to choose
Itamar Simonson (1989, Journal of Consumer Research) examined attraction and compromise effects from the perspective of reason-based choice. An option can become easier to defend when a local comparison clearly favours it, or when it occupies an intermediate position. The proposed mechanism does not require decision-makers to stop thinking: their search for a justification can itself make the comparison context influential.
The premature conclusion
It would be tempting to conclude that a weak offer necessarily manipulates the committee and should always be removed. These studies establish a possibility, not a rule applicable to every shortlist of suppliers or projects. An apparently inferior proposal may also provide relevant information, or offer an advantage on a criterion missing from the comparison table. (our executive and employee training programmes)
What the evidence does not allow us to assume
The cited experiments concern consumer choices with a limited set of attributes; they do not directly measure administrative or industrial decisions in Berne. In these settings, compliance, service continuity and institutional responsibilities can change the comparison. A shift in preference therefore proves neither intentional manipulation nor a decline in decision quality.
A practical check in Berne
Within SHR’s decision-making programme, an exercise using fictional cases can be adapted to federal administration procurement, public health, telecommunications or precision manufacturing in Berne. Randomly assign participants to a list containing two offers or to a version retaining those same offers, with identical attributes, but adding a proposal dominated by only one of them. Measure the difference between the proportions of participants choosing the offer that dominates the added proposal, retaining the lists and anonymised responses. This difference documents local sensitivity to shortlist composition; it does not establish which offer would be best in a real situation. To go further: explore the Decision-making training in Bern, or browse our executive and employee training programmes in Switzerland.
In pictures: Decision-making in Bern
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