Individual legislators can be important agents of political representation. However, this is contingent upon their responsiveness to constituency requests. To study this topic, an increasing number of studies use field experiments in which the researcher sends a standardized email to legislators on behalf of a constituent. In this paper, we report the results of an original field experiment of this genre with the members of the German Bundestag. Supplementing previous research, we explore whether constituency requests in which voters mention a personal vote intention (rather than a partisan vote intention) increase legislators’ responsiveness, and how this treatment relates to electoral system's incentives. We find that legislators treated with a personal vote intention were more likely to respond (67 per cent) and respond faster than those treated with a partisan vote intention (59 per cent). However, we also show that the treatment effect is moderated by electoral system incentives: it is larger for nominally-elected legislators than for those elected via a party list. Our results suggest that electoral system's incentives matter for legislators’ responsiveness only when constituents explicitly signals an intention to cast a personal vote.
