ABSTRACT
We concluded the previous chapter with the observation that estimates of the policy positions of political actors are raw material for many different approaches to analyzing political competition, but that there is no “one true way” to combine these positions into a single “best” multidimensional representation of the politics of any given political system. In this chapter we sketch the different ways in which spatial models have been used to illuminate various aspects of political competition, noting the different types of spatial representation of policy positions that each implies. We do not attempt a comprehensive review of the huge research program concerned with the spatial modeling of political competition, which has generated an enormous literature. Rather, we map out the general territory of the different types of spatial model that have been influential, considering the different types of need that each approach generates for reliable and systematic empirical estimates of the policy positions of political actors.
