Behavioral and Brain Sciences



Experimental practices in economics: A methodological challenge for psychologists?


Ralph Hertwig a1 and Andreas Ortmann a2
a1 Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, 14195 Berlin, Germany hertwig@mpib-berlin.mpg.de
a2 Center for Economic Research and Graduate Education, Charles University, and Economics Institute, Academy of Sciences of the Czech Republic, 111 21 Prague 1, Czech Republic andreas.ortmann@cerge.cuni.cz

Abstract

This target article is concerned with the implications of the surprisingly different experimental practices in economics and in areas of psychology relevant to both economists and psychologists, such as behavioral decision making. We consider four features of experimentation in economics, namely, script enactment, repeated trials, performance-based monetary payments, and the proscription against deception, and compare them to experimental practices in psychology, primarily in the area of behavioral decision making. Whereas economists bring a precisely defined “script” to experiments for participants to enact, psychologists often do not provide such a script, leaving participants to infer what choices the situation affords. By often using repeated experimental trials, economists allow participants to learn about the task and the environment; psychologists typically do not. Economists generally pay participants on the basis of clearly defined performance criteria; psychologists usually pay a flat fee or grant a fixed amount of course credit. Economists virtually never deceive participants; psychologists, especially in some areas of inquiry, often do. We argue that experimental standards in economics are regulatory in that they allow for little variation between the experimental practices of individual researchers. The experimental standards in psychology, by contrast, are comparatively laissez-faire. We believe that the wider range of experimental practices in psychology reflects a lack of procedural regularity that may contribute to the variability of empirical findings in the research fields under consideration. We conclude with a call for more research on the consequences of methodological preferences, such as the use on monetary payments, and propose a “do-it-both-ways” rule regarding the enactment of scripts, repetition of trials, and performance-based monetary payments. We also argue, on pragmatic grounds, that the default practice should be not to deceive participants.


Key Words: behavioral decision making; cognitive illusions; deception; experimental design; experimental economics; experimental practices; financial incentives; learning; role playing.