090514 Arieli

The Bernstein Center Freiburg

Bernstein Seminar

Amos Arieli

Department of Neurobiology
Weizmann Institute of Science
Rehovot, Israel

Decision-Making Motivations Revealed through Eye Movements

Abstract:
Neuroeconomics is a relatively new field in which researchers utilize information created non intentionally by decision makers in order to learn about the decision-making process in economic problems. The types of information used in Neuroeconomics include neural activity in the brain (as manifested in hemodynamic response and measured by fMRI), eye movements (as recorded by an eye tracker) and response time. Whether research in Neuroeconomics is indeed capable of making a fundamental contribution to Economics is currently a subject of intense debate.

In this study eye tracking was used to investigate decision makers’ motivations and procedures in two research questions. The first involved choice between two payment schemes, each of which specifies two amounts of money -- one to be paid to the participant and the other to an anonymous individual. We were interested in investigating whether people who make the “selfish” choice are being purely selfish or have arrived at the selfish decision after considering the effect of their choice on the size of the payment to the other individual. Eye movements provided evidence that participants were not motivated solely by selfishness: even when participants behaved selfishly, they nevertheless took into consideration the size of the payment to the other person. The second research question involves choice between simple lotteries. We attempt to determine whether decision makers evaluate each of the alternatives separately -- a choice strategy that is likely to be consistent with expected utility maximization -- or whether the decision is reached by comparing prizes and probabilities separately. Eye movements indicate that many participants based their decision on a comparison of prizes and probabilities rather than making an expected utility calculation.

Our results point out that individuals do systematically care about fairness considerations and have take it into account even though they have a wide range of factors, which could impact their decision. As a consequence, they tend to have the same considerations and motivations in similar decision-making situations. Different individuals assign different weights to the degree of concern to other people and, therefore, individuals differ in the tendency to prefer particular distributions of outcomes. In contrast, in a different dimension, in choice under uncertainty, individual are more flexible and consider the situation in which the behavior took place. Therefore, they solve the problem by moving from comparison of the relevant parameters to an expected-utility calculation. Do people use a more consistent procedure when making decisions that have a moral component? Future eye-tracking research perhaps could help to answer this question and others like it.

This work was done together with Yaniv Ben-Ami (School of Economics, Tel Aviv University) and Prof. Ariel Rubinstein (School of Economics, Tel Aviv University and Department of Economics, New York University).

Host: Prof. Dr. Stefan Rotter