Amos Tversky and Daniel Kahneman have shown that framing can affect
the outcome (ie. the choices one makes) of choice problems, to the
extent that several of the classic axioms of rational choice do not
hold. This is referred to as prospect theory[1]. Tversky and Kahneman
(1981) demonstrated systematic reversals of preference when the same
problem is presented in different ways, for example in the 'Asian
disease' problem. Participants were asked to "imagine that the U.S. is
preparing for the outbreak of an unusual Asian disease, which is
expected to kill 600 people. Two alternative programs to combat the
disease have been proposed. Assume the exact scientific estimate of the
consequences of the programs are as follows." The first group of
participants were presented with a choice between two programs:
* Program A: "200 people will be saved"
* Program B: "there is a one-third probability that 600 people will
be saved, and a two-thirds probability that no people will be saved"
72
percent of participants preferred program A (the remainder, 28 percent,
opting for program B). The second group of participants were presented
with the choice between:
* Program C: "400 people will die"
* Program D: "there is a one-third probability that nobody will die, and a two-third probability that 600 people will die"
In
this decision frame, 78 percent preferred program D, with the remaining
22 percent opting for program C. However, programs A and C, and
programs B and D, are effectively identical in accordance with
von-Neumann's expected utility hypothesis, in which the value of the
outcome of an event is multiplied by the probability of its occurrence.
A change in the decision frame between the two groups of participants
produced a preference reversal, with the first group preferring program
A/C and the second group preferring B/D. Edward Zelinsky has shown that
framing effects can explain some observed behaviors of legislators.