Data Analysis and Applications 2

14 Visualizing the Political Spectrum of Germany by Contiguously Ordering the Party Policy Profiles

The data from the German voting advice application (VAA), the Wahl-O-Mat, are used to empirically construct and visualize the political spectrum of Germany. For this purpose, we consider the positions of 28 German parties on 38 policy issues declared before the 2013 federal election and associate the parties with the 38-dimensional vectors of their policy profiles. These vectors are used to define the party proximity in the party space. Principal component analysis (PCA) reveals that the parties constitute a thin ellipsoid whose two longest diameters cover 83.4% of the total variance. Reducing the model to just these two dimensions, a one-dimensional party ordering is found, which is exactly the left-right axis rolled into a circumference, reflecting that the far-left and far-right ends of the political spectrum approach each other, although remain distant, resulting in its horseshoe-like shape.

14.1. Introduction

Discussing radical changes in the world order at the turn of the century, many political scientists started promoting the viewpoint that the left-right alignment of parties is becoming outdated (see, for instance, Giddens 1994; Manin 1997; Mitchell 2007; Voda 2014). It is argued that after the fall of the Soviet Union and Eastern Block, the class opposition lost the impetus of its inspiration by a systemic alternative. On the other hand, climate change, globalization, ...