In this spirit, I have placed studies into three groups: 1. Artefactual field experiments, which are the same as conventional lab experiments but with a non-standard subject pool (i.e., non-students). Running Peruvian borrowers through lab games (Karlan, 2005 AER) would be an example of an artefactual field experiment. 2. Framed field experiments, which are identical to artefactual field experiments but with field context in either the commodity, task, or information set that the subjects use. An example would be work that elicits valuations for public goods that occur naturally in the environment of the subjects (see some of Bohm's work). 3. Natural field experiments, which are identical to framed field experiments except that the subjects do not know that they are participants in an experiment. An example could be found among the recent surge in fundraising experiments (see, e.g., List and Lucking-Reiley, 2002, JPE).

Of course, not all studies will fit neatly into one of these three categories. I hope, however, that the categories provide a useful way to think about the factors outside of a traditional laboratory experiment that are potentially important. I hope that you find the site useful – I am sure that many studies are missing and therefore I will update the site often in an attempt to provide an informative source on field experiments. Accordingly, corrections and suggestions are welcome: JList@uchicago.edu.

I would like to especially thank Dean Karlan, who had the idea to completely overhaul the site and allow submissions via the new on-line system. He also spearheaded the changes to the site. Also, thanks to Nathaniel Higgins, Michael Price, and Jeff Cunningham for assistance. For online and personal use only, all rights reserved (John List and Dean Karlan). If you would like to post a study or find that I am missing a study, please send me a message at fieldexperiments@arec.umd.edu.