Risk attitudes, randomization to treatment, and self-selection into experiments
Randomization to treatment is fundamental to statistical control in the design of experiments. But randomization implies some uncertainty about treatment condition, and individuals differ in their preferences towards taking on risk. Since human subjects often volunteer for experiments, or are allowed to drop out of the experiment at any time if they want to, it is possible that the sample observed in an experiment might be biased because of the risk of randomization. On the other hand, the widespread use of a guaranteed show-up fee that is non-stochastic may generate sample selection biases of the opposite direction, encouraging more risk averse samples into experiments. We undertake a field experiment to directly test these hypotheses that risk attitudes play a role in sample selection. We follow standard procedures in the social sciences to recruit subjects to an experiment in which we measure their attitudes to risk. We exploit the fact that we know certain characteristics of the population sampled, adults in Denmark, allowing a statistical correction for sample selection bias using standard methods. We also utilize the fact that we have a complex sampling design to provide better estimates of the target population. Our results suggest that randomization bias is not a major empirical problem for field experiments of the kind we conducted if the objective is to identify marginal effects of sample characteristics. However, there is evidence that the use of show-up fees may have generated a sample that was more risk averse than would otherwise have been observed.
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Glenn Harrison & Morten Lau & Elisabet Rutstrom & Melonie Williams, 2002.
"Estimating individual discount rates in denmark: A field experiment,"
Artefactual Field Experiments
00062, The Field Experiments Website.
- Glenn W. Harrison & Morten I. Lau & Melonie B. Williams, 2002. "Estimating Individual Discount Rates in Denmark: A Field Experiment," American Economic Review, American Economic Association, vol. 92(5), pages 1606-1617, December.
- Glenn W. Harrison & Morten I. Lau & Melonie B. Williams, 2001. "Estimating Individual Discount Rates in Denmark: A Field Experiment," NCEE Working Paper Series 200102, National Center for Environmental Economics, U.S. Environmental Protection Agency, revised Nov 2001.
- Heckman, James J. & Robb, Richard Jr., 1985. "Alternative methods for evaluating the impact of interventions : An overview," Journal of Econometrics, Elsevier, vol. 30(1-2), pages 239-267.
- David Reiley & John List, 2008.
Artefactual Field Experiments
00091, The Field Experiments Website.
- Steffen Andersen & Glenn W. Harrison & Morten I. Lau & E. Elisabet Rutström, 2008. "Eliciting Risk and Time Preferences," Econometrica, Econometric Society, vol. 76(3), pages 583-618, 05.
- James J. Heckman & Jeffrey A. Smith, 1995. "Assessing the Case for Social Experiments," Journal of Economic Perspectives, American Economic Association, vol. 9(2), pages 85-110, Spring.
- Glenn W. Harrison & Morten I. Lau & E. Elisabet Rutström, 2007.
"Estimating Risk Attitudes in Denmark: A Field Experiment,"
Scandinavian Journal of Economics,
Wiley Blackwell, vol. 109(2), pages 341-368, 06.
- Elisabet Rutstrom & Glenn Harrison & Morten Lau, 2004. "Estimating risk attitudes in denmark: A field experiment," Artefactual Field Experiments 00059, The Field Experiments Website.
- Steffen Andersen & Glenn W. Harrison & Morten I. Lau & E. Elisabet Rutström, 2008. "Lost In State Space: Are Preferences Stable?," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 49(3), pages 1091-1112, 08.
- Dan Lovallo & Colin Camerer, 1999. "Overconfidence and Excess Entry: An Experimental Approach," American Economic Review, American Economic Association, vol. 89(1), pages 306-318, March.
- Palfrey, Thomas R. & Pevnitskaya, Svetlana, 2003.
"Endogenous Entry and Self-selection in Private Value Auctions: An Experimental Study,"
1172, California Institute of Technology, Division of the Humanities and Social Sciences.
- Palfrey, Thomas R. & Pevnitskaya, Svetlana, 2008. "Endogenous entry and self-selection in private value auctions: An experimental study," Journal of Economic Behavior & Organization, Elsevier, vol. 66(3-4), pages 731-747, June.
- Glenn W. Harrison & Eric Johnson & Melayne M. McInnes & E. Elisabet Rutström, 2005. "Temporal stability of estimates of risk aversion," Applied Financial Economics Letters, Taylor and Francis Journals, vol. 1(1), pages 31-35, January.
- James J. Heckman, 1976. "The Common Structure of Statistical Models of Truncation, Sample Selection and Limited Dependent Variables and a Simple Estimator for Such Models," NBER Chapters, in: Annals of Economic and Social Measurement, Volume 5, number 4, pages 475-492 National Bureau of Economic Research, Inc.
- Francis Vella, 1998. "Estimating Models with Sample Selection Bias: A Survey," Journal of Human Resources, University of Wisconsin Press, vol. 33(1), pages 127-169.
- Heckman, James J, 1979.
"Sample Selection Bias as a Specification Error,"
Econometric Society, vol. 47(1), pages 153-61, January.
- Mitali Das & Whitney K. Newey & Francis Vella, 2003. "Nonparametric Estimation of Sample Selection Models," Review of Economic Studies, Oxford University Press, vol. 70(1), pages 33-58.
- Charles A. Holt & Susan K. Laury, 2002. "Risk Aversion and Incentive Effects," American Economic Review, American Economic Association, vol. 92(5), pages 1644-1655, December.
- Elisabet Rutstrom & Glenn Harrison & Melonie Williams & Morten Lau, 2006. "Eliciting risk and time preferences using field experiments: Some methodological issues," Artefactual Field Experiments 00063, The Field Experiments Website.
When requesting a correction, please mention this item's handle: RePEc:feb:artefa:00061. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Joe Seidel)
If references are entirely missing, you can add them using this form.