Due to its mixed member proportional system (MMP), the German Bundestag is a popular subject for the study of the effects of the electoral system on styles of representation. Although the theoretical groundwork would imply that the MMP-system creates two distinct types of MP, one more oriented toward the party, the other more oriented toward his constituency, empirical studies have shown inconclusive evidence of such an effect. Recent studies have demonstrated that contamination effects between the candidacy modes wash-out any direct effects on the representation style of members of the Bundestag. Sieberer (2010) on the other hand, has shown evidence of an effect of the electoral mode on the tendency to deviate from the party group line. This would imply that district MPs may be more inclined to represent local interest. Using roll-call data from the 16th and the ongoing 17th Bundestag, this paper analyses whether elected representatives behave differently according to the mode of their election (i.e. direct or via party lists), while also considering preferences, issue salience and structural data of the electoral districts. These controls are often neglected in the discourse of institutional effects on legislative behaviour. I argue that while the institutional argument is central, it makes little sense to discuss representation, without taking these three additional factors into account. Preferences which are linked to issue salience are at the core of the neo-institutional argument. Linking legislative behaviour to the characteristics of the electoral district, such as levels of education, affluence and unemployment, this paper analyses whether different forms of representation are dependent on the constituency MPs represent. Put differently, it analyses whether some electoral districts more successful in choosing an MP who will represent their local interest. To analyse these effects on the individual level behaviour of an MP, a hierarchical model which includes individual, district and system level factors, will be implemented.
