Parties' Electoral System Incentives

The impact of the electoral system was very interesting to me. Professor King demonstrated clearly that the type of electoral system one chooses tends to advantage some interests while disadvantaging others, which explains why designing these systems could be so contentious. However, once these systems have been designed, they are probably very hard to change without some great pressure from the representatives’ constituents. To be more specific, regarding a plurality system, by Duverger’s Law, we may anticipate that two political parties will dominate politics. These parties have a vested interest in maintaining the plurality electoral system, which provides them with a higher percentage of the seats then would a proportional representative system, which would encourage the establishment of multiple parties. Therefore, converting a plurality system to a proportional representative system would seem highly unlikely if the impetus must come from the two parties in power.

In a proportional representative system the factors would become more complex. If we assume that every party would like to maximize its seats, then different parties may favor different electoral systems depending upon their size. For example, small parties would favor a more proportional representation, which would help them gain seats. Larger parties, especially the largest, might favor a plurality system, which would increase their number of seats as plurality began disadvantage the smaller parties. These varying interests exist in all of the different system and help explain why nations might change their system. For example, Benjamin Reilly mentioned that Papa New Guinea changed their system from alternate vote to a plurality and Estonia from a single transferable vote to a proportional list system when politicians realized it would be in their interest (and help their party win seats) to change it. In more stable democracies, these systems probably become entrenched, as the advantage gain more seats due to the electoral system, so control the power and are incentivized to maintain it. I would suspect it takes some outside force to encourage politician to change it.