Harrison and List:Field Experiments 1011 literature review is necessarily selective material,language,animal,etc.,and not in although List(2004d)offers a more complete the laboratory,study,or office."This orients bibliography. us to think of the natural environment of the In sections 7 and 8 we review two types of different components of an experiment. It is impe ortant to identify what factors xperiments.One is called a social p riment so that we that it is a delib a what facto cial re di peri ma mot ivate ample when pe of some governmen progr n is implemented periment that diffe They have become popular in ce areas counterpart lab experiments o f Ronald such as employment schemes and the detec ummings,Glenn Harrison,anc Laura tion of discrimination.Their disadvantages Osborne (1995)and Cummings and Laura have been well documented.given thei Tavlor (1999).what explains the differencer political popularity,and there are several Is it the use of data from a particular marke important methodological lessons from those whose participants have selected into the debates for the design of field experiments. market instead of student subjects;the use The other is called a"natural experiment. of subjects with experience in related tasks: The idea is to recognize that som event that the use of private sports-cards as the under naturally occurs in the field ha ens to have odity instead of an environme som e of the characteristics of a field e lying co tal wd. the of streamlined me nt The an be attra ctive sc sof dat ntal thods the less-intrusive e at e cost due to mun some combin and simila cing the certai Finally,in section S we briefly exa related types of experiments of the mind.In ed.)defines the one case these are the thought exper tion ments"of theorists and statisticians.and in rgnltcgetonofohowyome the other they are the ord means "neuro-economics experiments" provided by technology. The dane things objective is simply to identify how they differ minded that d to be son 2.Defining Field Experiment ethingo y on to bes Th e are several ways to define One is asc ormal d b up ir onary.An Eve n tha identify w t it is that you want the I to differen o阳ere is the lab The Oxf ord English Dictionary (Secon Edition)defines the word"field"in the fol ory of the in publi policy.If th is son lowing manner: "Used attributively to hat rem denote an investigation,study,etc.,carried optimum,itdoe natic out in the natural environment of a given to the optimum