Bringing the Lab to the Field and the Field to the Lab : More than Changing Subjects

This paper argues that when conducting experiments in the field it is equally valuable to bring the lab to the field as well as bringing the field to the lab, that is, there might not be such trade-off between control and relevance. The paper offers a series of reflections and lessons from conducting economic experiments outside of the campus laboratory where one finds richer contexts, more variable demographics among the experimental participants, and more complex dynamics and interactions ex-ante and ex-post the experiment itself. These lessons are based on the author’s experience of seven years of conducting experiments in the field, with about three hundred sessions and some 1,800 participants, mostly on common-pool resource and public goods games conducted in rural villages in Colombia, and replications with college students. Among the main lessons are i) the actual environment and institutions outside of the field lab can help explain experimental behavior and therefore there is need for better understand of such contextual factors that the participants usually face. Thus, greater variation in the demographics across subjects within a field site, and replicating experiments across field sites can provide major gains in explaining variation in behavior; ii) replicating experiments with participants in the field and students can enrich the analysis, strengthen the internal validity of the experiments, but also when differences are found, it can provide elements for interpreting results from experiments with students; and iii) re-visiting the same field lab can bring unexplored elements about the long run dynamics in social exchange situations that can rarely be created in short-run experiments. Further, the paper invites experimentalists to improve their observation in the field lab by complementing the experimental data with other tools and dialogues with the experimental participants –called ‘subjects’ by othersto better interpret results. 1 Samuel Bowles, Jack Knetsch and Andreas Ortmann have enriched the arguments with their comments to previous drafts. Many discussions with Jeff Carpenter, Abigail Barr, and Justine Burns have polished these ideas greatly and it would be hard to distinguish from their authorship sometimes. Ernst Fehr generously helped to part of the experimental design generating data used in this paper. Diana Maya and Maria Claudia Lopez provided important input and analysis of qualitative data within various projects, and most of the field work during the 2000-2003 years could not have been done without them. Special thanks to Pablo Ramos, Ana María Roldán and Liliana Mosquera and their help in the field. Also, I wish there was room in our papers to list the names of the almost two thousand participants in the field that offered insights about human behavior through their discussions and participation in the experiments. Funding for much of the field work supporting the paper is from a Research & Writing Grant from the John D. and Catherine T. Macarthur Foundation, the Preferences Network headed by Rob Boyd and Herb Gintis, and the Santa Fe Institute. A previous version of the paper was presented at the 2005 American Economics Association meetings, Philadelphia and at the 2003 International Meeting of the Economic Science Association, Pittsburgh.