Gains v. losses, or context dependence generated by confusion?

Abstract

Tversky and Kahneman introduced the term framing for the finding that people give different answers to the same question depending on the way it is posed. One form of framing involves presenting the same outcome as either a gain or a loss. An experiment on starlings by Marsh and Kacelnik suggests that this form of framing occurs in non-humans. We argue that the experimental result demonstrates framing in the general sense of context dependence but does not provide compelling evidence of framing in terms of gains and losses. A version of scalar utility theory which is extended to include the possibility of memory errors accounts for the data and suggests future lines of research.

Keywords: Framing; Scalar utility theory.

Fig. 1

Predictions of the memory model (Eq. 4). Parameters are chosen as in Marsh and Kacelnik (2002), i.e. $a=2,b=6,f=4,p_a=0.5,s=1$ (gains) and $s=7$ (losses), for various values of $\theta$. The dashed black line is the SUT prediction, i.e. $\theta =0$ (colour online)

Fig. 2

Predictions of SUT (Eq. 2) for the parameter values used in three choice experiments with starlings (Reboreda and Kacelnik ; Bateson and Kacelnik ; Brito e Abreu and Kacelnik 1999) (see text). The values of the experimental observations are shown as straight lines (colour online)