ABSTRACT
The spatial models of political competition we discuss in the previous chapter can be constructed either at the level of pure theory, or in a form that allows them to address politics in the real world. Many formal models are in effect self-contained and stylized “Platonic” systems of assumed motivations, institutions, and rules of interaction. Yet, at the same time, the authors of these models typically name the concepts they use in ways that refer suggestively to the real world. Thus modeled agents such as “voters” and “politicians” are given these sobriquets precisely because the claim is being made, at least implicitly and often explicitly, that these theoretical abstractions from reality do bear some meaningful resemblance to wet-life human “voters” and “politicians” who can actually be observed and touched. This in turn is often taken to imply, even if only rhetorically, that analytical implications of the theoretical model have something to do with reality. Indeed the authors of such models are only very rarely satisfied to present us with a purely Platonic system adorned with “political” labels – however beautiful this system might be. They are typically concerned to argue, often surprisingly informally, that their model addresses some aspect of real political competition. This brings us back to Reichenbach's distinction, discussed in Chapter 1, between mathematical and physical geometries – with the latter an essentially empirical enterprise that involves measuring the real-world. In the present context this means that the development of physical, as opposed to mathematical, spatial models of political competition depends upon the creation of a set of measuring rods that can be used to describe real-world spatial locations. In this chapter, we consider alternative types of such metaphorical measuring rods, and the extent to which different types of measurement instrument may be suitable for different types of spatial models.
