1012 Journal of Economic Literature,Vol.XLII (December 2004 differences?We believe field experiments Blackburn,Harrison,and have mature d to the point that some frame. Rutstrom 1994).Alternatively,the subject work for addressing such differences in a pool can be designed to represent a target systematic manner is necessary. population of the econom (e.g.,traders at 2.1 Criteria that Define Field Experiments the Chicago Board of Trade in Michael Haigh and John List 2004)or the general Running the risk of oversimplifying what oulation (e.g.,the Danish population in is inherently a multidimensional iss we rison.Morton Igel Lat. and Melonie Williams 2002). riment addition. the nature of the subject po monstandard subject p rience with the commodit ·the nat of the info mation that the the tasl exper apar the e nature o the task In the mg ce of the or trading rules to their trading activities in applied addition to their knowledge of e trading the nature of the stakes,and institution In abstract settings the impo the nature of the environment that the tance of this information is diminished.by subject operates in. design.and that can lead to behavioral We recognize at the outset that these changes.for example.absent such informa characteristics will often be correlated to tion.risk aversion can lead to subjects varying degrees.Nonetheless.they can be requiring a risk premium when bidding for used to propose a taxonomy of field experi objects with uncertain characteristics. ments that will,we believe,be valuable as The commodity itself can be an ir een lab and field experi tant part of the field.Re mental results become common ent years seen ents er can be ed as the used by valua g000 ha menters ions ove rtual g00 ie ce sa when n physical s or use s field subje ts,th abstra ly de goods latte as nonstandar in this have been the staple of xperimental eco e.But we a argu that the use of onstar nomics since Edward Chamberlin (1948) and Vernon Smith(1962),but impo ses ar ify the experiment as a field experiment.The artificiality that could be a factor influenc experiments of Cummings,Harrison,and E ing behavior.'Such influences are actually Elizabet Rutstrom(1995),for example,used of great interest,or should be.If the nature individuals recruited from churches in order of the commodity itself affects behavior in to obtain a wider range of demographic that is not accounted for by thethe characteristics than one would obtain in the has at standard college setting.The im of be st a lin domain of a a nonstandard subiect aries fron should be aw t worse ment to nt.in this ply false In on y pro et of soc cha Smith(962sgi3t mportan when dev loping statistica gh Smith (1962)does models to adjust for hypothetical bias p.121)in which monetary payoffs were employed