Strategic mobilization: Why proportional representation decreases voter mobilization

• I present a formal model showing that proportional rules reduce the incentives to mobilize voters.
• Mobilization is higher in competitive plurality contests than proportional contests.
• I conclude that proportional rules increase turnout in spite of incentives to mobilize, if at all.

Many scholars suggest that proportional representation increases party mobilization by creating nationally competitive districts that give parties an incentive to mobilize everywhere. This paper provides theoretical and empirical arguments that bring this claim into question. I propose, unlike earlier scholars, that the positive effect of district competitiveness on party mobilization efforts increases as electoral districts become more disproportional, arguing that disproportionality itself encourages mobilization by exaggerating the impact of competitiveness on mobilization. Individual-level survey data from national legislative elections show that competitiveness has a much larger positive effect on parties' mobilization efforts in single-member districts than in proportional districts. Contrary to prior literature, these results suggest proportional electoral rules give parties no strong incentive to mobilize anywhere.