Microeconomics SeminarSuccesful Voting in Weighted Committees and Shareholder MeetingsStefan Napel (Universität Bayreuth), VMP 5 (Room 0079)

13 November 2025

Abstract: The applicable voting rule determines how closely collective decisions between three or more options reflect the preferences of a given individual. We construct measures of this and ask if a specific decision maker is more successful using plurality voting, plurality with a runoff vote, pairwise majority voting or the Borda scoring method. Our first benchmark finding is that if all voting weights are equal, then plurality rule maximizes the probability of obtaining one's individual top choice and Borda rule maximizes the voter-specific average ranking of the outcome. This result generalizes to asymmetric weights in aggregate terms but not from a single voter's perspective. We use computational methods to identify the individually most advantageous rule for any given weight distribution among three generic voters and also for the ten largest shareholders in S&P 100 corporations. Practical recommendations for the latter coincide in unexpectedly many cases with the analytical benchmark for equal weights. We also find that the Borda rule translates voting weights into voting success the most transparently and that traditional power indices for binary voting games approximate success in weighted committees well