What does one learn from reading about economics experiments? This:
“Self-Selection into Economics Experiments Is Driven by Monetary Rewards,” Johannes Abeler [University of Oxford, IZA and CESifo] and Daniele Nosenzo [University of Nottingham], IZA [Forschungsinstitut zur Zukunft der Arbeit / Institute for the Study of Labor] DP No. 7374, April 2013. The researchers explain:
“Laboratory experiments have become a wide-spread tool in economic research. Yet, there is still doubt about how well the results from lab experiments generalize to other settings. In this paper, we investigate the self-selection process of potential subjects into the subject pool. We alter the recruitment email sent to first-year students, either mentioning the monetary reward associated with participation in experiments; or appealing to the importance of helping research; or both. We find that the sign-up rate drops by two-thirds if we do not mention monetary rewards. Appealing to subjects’ willingness to help research has no effect on signup. We then invite the so-recruited subjects to the laboratory to measure a range of preferences in incentivized experiments. We do not find any differences between the three groups. Our results show that student subjects participate in experiments foremost to earn money, and that it is therefore unlikely that this selection leads to an over-estimation of social preferences in the student population.”
(Thanks to investigator Dan Vergano for bringing this to our attention, and for supplying the headline.)