Experiments versus models: New phenomena, inference and surprise

Abstract

A comparison of models and experiments supports the argument that although both function as mediators and can be understood to work in an experimental mode, experiments offer greater epistemic power than models as a means to investigate the economic world. This outcome rests on the distinction that whereas experiments are versions of the real world captured within an artificial laboratory environment, models are artificial worlds built to represent the real world. This difference in ontology has epistemic consequences: experiments have greater potential to make strong inferences back to the world, but also have the power to isolate new phenomena. This latter power is manifest in the possibility that whereas working with models may lead to 'surprise', experimental results may be unexplainable within existing theory and so 'confound' the experimenter.

Experiments, Simulations, and Epistemic Privilege

“…These trends are reflected in increased attention from philosophers of science to experimentation (e.g. , Franklin 1990;Hacking 1983;Radder 2003;Weber 2004), to simulation (e.g., Humphreys 2004;Weisberg 2013;Winsberg 2010), and to their methodological and epistemic points of convergence and contrast (e.g., Barberousse et al 2008;Guala 2002;Morgan 2005;Morrison 2009;Parker 2009;Peck 2004;Peschard 2012;Winsberg 2009). …”

“…Winsberg nicely describes this as "the suspicion (or conviction) [that] the experimenter simply has more direct epistemic access to her target than the simulationist does" (2010,55). Morgan (2005) and Guala (2002) have argued that material object-target correspondence is a defining feature of experiments, and that this correspondence is responsible for experiments' advantage over simulations in terms of inferential power. I will call this shared view of theirs the materiality thesis.…”

“…To think through what this means exactly, we first need to clarify what this correspondence is supposed to consist in. Morgan and Guala refer to it in various ways: "material correspondence," "material analogy, "ontological equivalence," or being "made of the same stuff" (Guala 2002;Morgan 2005). They must of course mean "made of the same kind of stuff," in the sense that object and target are both instances of the same material type.…”

“…The picture is further complicated because proponents of the materiality thesis compare experiment to simulation in the broader sense (Guala 2002;Morgan 2005), while its opponents have sometimes followed suit (Winsberg 2010) and sometimes focused only on computer simulation (Parker 2009). I mentioned in Section 1 that it is particularly difficult to establish a difference between experiment and simulation in the broader sense.…”

The Role of Experiments for the Development of Economic Theories

“…In a lab experiment control is achieved through the experimental design and the physical restrictions imposed on the experimental 8 For a similar view of models and experiments see Morrison and Morgan (1999) and Morgan (2005). 9 See e.g.…”