Theory, Experimental Design and Econometrics Are Complementary (And So Are Lab and Field Experiments)

Experiments are conducted with various purposes in mind including theory testing, mechanism design and measurement of individual characteristics. In each case a careful researcher is constrained in the experimental design by prior considerations imposed either by theory, common sense or past results. We argue that the integration of the design with these elements needs to be taken even further. We view all these elements that make up the body of research methodology in experimental economics as mutually dependant and therefore take a systematic approach to the design of our experimental research program. Rather than drawing inferences from individual experiments or theories as if they were independent constructs, and then using the findings from one to attack the other, we recognize the need to constrain the inferences from one by the inferences from the other. Any data generated by an experiment needs to be interpreted jointly with considerations from theory, common sense, complementary data, econometric methods and expected applications. We illustrate this systematic approach by reference to a research program centered on large artefactual field experiments we have conducted in Denmark. An important contribution that grew out of our work is the complementarity between lab and field experiments.