Academic Journals Database
Disseminating quality controlled scientific knowledge

A methodological approach to ratio bias

Author(s): Gabriella Passerini | Laura Macchi | Maria Bagassi

Journal: Judgment and Decision Making
ISSN 1930-2975

Volume: 7;
Issue: 5;
Start page: 602;
Date: 2012;
VIEW PDF   PDF DOWNLOAD PDF   Download PDF Original page

Keywords: ratio bias | probability judgment.NAKeywords

The ratio-bias (RB) phenomenon is considered to provide systematic evidence of irrationality. When judging the probability of a low-probability event, many people judge it as less likely when it is expressed as a ratio of small numbers (e.g., 1-in-10) than when it is expressed as a ratio of large numbers (e.g., 10-in-100). Four experiments show that the phenomenon is increased by the experimental paradigm, which misleads subjects regarding the aim of the task by inducing equal-ratio neglect. One factor is constant across the texts of the Experiment 1--3: a particular sentence that induces subjects to neglect the equal ratio and invites them to express feelings about the outcome of the target event rather than giving a rational answer. This intent is strengthened by the formulation of the question (Experiment 1), which explicitly asks the subject to express the FEELING connected to the lotteries and the absence of a third option (Experiment 1, 4), the right one, which expresses the ``indifference'' between the two options. In Experiment 4, the task lacks only the third option, and, simply by adding the option that allows subjects to express the correct answer, the RB disappears.

Tango Rapperswil
Tango Rapperswil

     Save time & money - Smart Internet Solutions