committee work more efficient by excluding smaller parties. The rule change contributed to the loss of the KPD’s committee assignments. It would have meant the same for the nine Zentrum and thirteen BP deputies had they not joined together in the newly formed FU. Similarly, the 7 WAV deputies retained their committee assignments by joining the DP. (Kaack 1972, 21) These party switches had no significant overall effect, reducing the ENPP from 4.01 to 3.98.
Most rational choice scholars model treat political parties as member-less and infrastructure-free coalitions of office seekers who continuously re-evaluate their membership. (Aldrich 1995; Geddes 1994; Laver and Shepsle 1999) This conceptualization, while empirically inaccurate, has the theoretical merit of highlighting the propensity of politicians to switch their party affiliations under certain conditions and, when doing so, altering a party system between elections. Such switches usually are accompanied by personality disputes or factional squabbles which generate considerable publicity and therefore provide voters with information about parties’ changing electoral prospects. The amount of switching and the specific types of switches are key for understanding how they ultimately affect strategic voting; the more switching pools seats, the more likely voters will upgrade the winning chances of the party attracting the switchers and vote for them and vice versa.
Frequency and Types of Switching: Table 5 provides information about the frequency and the nature of German party switchers. The first row indicates that switching was a temporary phenomenon - with the number of switchers declining rapidly and disappearing altogether after 1961. The second row identifies switchers according to the size of their party of origin; it shows that switchers originating from minor parties account for most switches. This is hardly surprising given the fact that small parties’ precarious existence made them unattractive both to existing members contemplating defection as well as prospective joiners from other parties. By contrast, the major parties experienced much lower levels of switching because they provided more secure career paths for their members. Deputies leaving one the three big parties almost always did so because of important policy differences rather than uncertainty about their careers. Such a